Microsoft.AspNetCore.SignalR.Protocols.MessagePack
Implements the SignalR Hub Protocol over MsgPack. This package was built from the source code at https://github.com/dotnet/dotnet/tree/3551975be08744f0418857c5bed8ab1545c5dd47
Activity
- Latest release
- 5d ago
- Total releases
- 267
- Cadence
- ~daily
- Last 12 months
- 48
Details
- License
- MIT
- First release
- May 06, 2018
| Version | Released | |
|---|---|---|
9.0.20
patch
|
9.0.20
patch
Dependencies (2)
|
|
10.0.12
patch
|
10.0.12
patch
Dependencies (2)
|
|
8.0.31
patch
|
8.0.31
patch
Dependencies (2)
|
|
11.0.0-rc.1.26425.128
pre
|
11.0.0-rc.1.26425.128
pre
Dependencies (2)
|
|
9.0.19
patch
|
9.0.19
patch
Dependencies (2)
|
|
10.0.11
patch
|
10.0.11
patch
Dependencies (2)
|
|
8.0.30
patch
|
8.0.30
patch
Dependencies (2)
|
|
11.0.0-preview.7.26381.103
pre
|
11.0.0-preview.7.26381.103
pre
Dependencies (2)
|
|
9.0.18
patch
|
9.0.18
patch
Dependencies (2)
|
|
10.0.10
patch
|
10.0.10
patch
Dependencies (2)
|
|
8.0.29
patch
|
8.0.29
patch
Dependencies (2)
|
|
11.0.0-preview.6.26359.118
pre
|
11.0.0-preview.6.26359.118
pre
Dependencies (2)
|
|
1.2.11
patch
|
1.2.11
patch
Dependencies (3)
|
|
9.0.17
patch
|
9.0.17
patch
Dependencies (2)
|
|
10.0.9
patch
|
10.0.9
patch
Dependencies (2)
|
|
8.0.28
patch
|
8.0.28
patch
Dependencies (2)
|
|
11.0.0-preview.5.26302.115
pre
|
11.0.0-preview.5.26302.115
pre
Dependencies (2)
|
|
1.2.10
patch
|
1.2.10
patch
Dependencies (3)
|
|
9.0.16
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
9.0.16
patch
Dependencies (2)
|
|
10.0.8
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
10.0.8
patch
Dependencies (2)
|
|
8.0.27
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
8.0.27
patch
Dependencies (2)
|
|
11.0.0-preview.4.26230.115
pre
|
11.0.0-preview.4.26230.115
pre
Dependencies (2)
|
|
10.0.7
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
10.0.7
patch
Dependencies (2)
|
|
9.0.15
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
9.0.15
patch
Dependencies (2)
|
|
8.0.26
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
8.0.26
patch
Dependencies (2)
|
|
10.0.6
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
10.0.6
patch
Dependencies (2)
|
|
11.0.0-preview.3.26207.106
pre
|
11.0.0-preview.3.26207.106
pre
Dependencies (2)
|
|
10.0.5
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
10.0.5
patch
Dependencies (2)
|
|
11.0.0-preview.2.26159.112
pre
|
11.0.0-preview.2.26159.112
pre
Dependencies (2)
|
|
9.0.14
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
9.0.14
patch
Dependencies (2)
|
|
8.0.25
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
8.0.25
patch
Dependencies (2)
|
|
10.0.4
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
10.0.4
patch
Dependencies (2)
|
|
11.0.0-preview.1.26104.118
pre
|
11.0.0-preview.1.26104.118
pre
Dependencies (2)
|
|
9.0.13
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
9.0.13
patch
Dependencies (2)
|
|
10.0.3
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
10.0.3
patch
Dependencies (2)
|
|
8.0.24
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
8.0.24
patch
Dependencies (2)
|
|
9.0.12
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
9.0.12
patch
Dependencies (2)
|
|
10.0.2
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
10.0.2
patch
Dependencies (2)
|
|
8.0.23
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
8.0.23
patch
Dependencies (2)
|
|
1.2.9
patch
|
1.2.9
patch
Dependencies (3)
|
|
1.2.8
patch
|
1.2.8
patch
Dependencies (3)
|
|
10.0.1
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
10.0.1
patch
Dependencies (2)
|
|
10.0.0
major
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
10.0.0
major
Dependencies (2)
|
|
9.0.11
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
9.0.11
patch
Dependencies (2)
|
|
8.0.22
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
8.0.22
patch
Dependencies (2)
|
|
9.0.10
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
9.0.10
patch
Dependencies (2)
|
|
8.0.21
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
8.0.21
patch
Dependencies (2)
|
|
10.0.0-rc.2.25502.107
pre
|
10.0.0-rc.2.25502.107
pre
Dependencies (2)
|
|
9.0.9
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
9.0.9
patch
Dependencies (2)
|
|
8.0.20
patch
1 CVE
CVE-2026-45591
GHSA-f8h2-vmm9-qhj6
BIT-aspnet-core-2026-45591
BIT-dotnet-2026-45591
BIT-dotnet-sdk-2026-45591
Jun 15, 2026
Microsoft Security Advisory CVE-2026-45591 – ASP.NET Core Denial of Service Vulnerability
7.5
/ 10
High
Network
Low
None
None
Unchanged
None
None
High
Executive summaryMicrosoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core SignalR and Blazor Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the MessagePack hub protocol used by SignalR and Blazor Server where an attacker can send deeply-nested MessagePack arrays to cause a stack overflow, resulting in a denial of service. AnnouncementAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/405 Affected Platforms
Affected PackagesThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below .NET 10Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.8 | 10.0.9 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 10)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 10.0.0, <= 10.0.8 | 10.0.9 .NET 9Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.16 | 9.0.17 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 9)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 9.0.0, <= 9.0.16 | 9.0.17 .NET 8Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.osx-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.27 | 8.0.28 Microsoft.AspNetCore.SignalR.Protocols.MessagePack (.NET 8)Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.SignalR.Protocols.MessagePack | >= 8.0.0, <= 8.0.27 | 8.0.28 Advisory FAQHow do I know if I am affected?If using a package listed in affected packages, you're exposed to the vulnerability. How do I fix the issue?
Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other InformationReporting Security IssuesIf you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ. Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty. SupportYou can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/aspnetcore. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. DisclaimerThe information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. AcknowledgementsAnonymous Affected versions
8.0.0
8.0.1
8.0.10
8.0.11
8.0.12
8.0.13
8.0.14
8.0.15
8.0.16
8.0.17
8.0.18
8.0.19
+ 41 more Show less
8.0.2
8.0.20
8.0.21
8.0.22
8.0.23
8.0.24
8.0.25
8.0.26
8.0.27
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.0.8
9.0.0
9.0.1
9.0.10
9.0.11
9.0.12
9.0.13
9.0.14
9.0.15
9.0.16
9.0.2
9.0.3
9.0.4
9.0.5
9.0.6
9.0.7
9.0.8
9.0.9
10.0.0
10.0.1
10.0.2
10.0.3
10.0.4
10.0.5
10.0.6
10.0.7
10.0.8
Fixed in
8.0.28
9.0.17
10.0.9
References
Updated Sep 10, 2026 · Source: OSV.dev |
8.0.20
patch
Dependencies (2)
|