actix-http

Version	Released
`3.13.5` patch	Sep 02, 2026
`3.13.4` patch	Sep 02, 2026
`3.13.3` patch	Aug 09, 2026
`3.13.2` patch	Aug 07, 2026
`3.13.1` unknown	Jun 22, 2026
`3.13.0` unknown	Jun 21, 2026
`3.12.1` unknown	Apr 18, 2026
`3.12.0` unknown 1 CVE	Feb 18, 2026
`3.11.2` unknown 1 CVE	Oct 05, 2025
`3.11.1` unknown 1 CVE	Aug 26, 2025
`3.11.0` unknown 1 CVE	May 10, 2025
`3.10.0` unknown 1 CVE	Mar 10, 2025
`3.9.0` unknown 1 CVE	Aug 10, 2024
`3.8.0` unknown 1 CVE	Jun 19, 2024
`3.7.0` unknown 1 CVE	May 19, 2024
`3.6.0` unknown 1 CVE	Feb 04, 2024
`3.5.1` unknown 1 CVE	Dec 25, 2023
`3.5.0` unknown yanked 1 CVE	Dec 24, 2023
`3.4.0` unknown 1 CVE	Aug 29, 2023
`3.3.1` unknown 1 CVE	Mar 02, 2023
`3.3.0` unknown 1 CVE	Jan 21, 2023
`3.2.2` unknown 1 CVE	Sep 11, 2022
`3.2.1` unknown 1 CVE	Jul 02, 2022
`3.2.0` unknown 1 CVE	Jul 01, 2022
`3.1.0` unknown 1 CVE	Jun 11, 2022
`3.0.4` unknown 1 CVE	Mar 09, 2022
`3.0.3` unknown 1 CVE	Mar 08, 2022
`3.0.2` unknown 1 CVE	Mar 05, 2022
`3.0.1` unknown 1 CVE	Mar 04, 2022
`3.0.0` unknown 1 CVE	Feb 25, 2022
`3.0.0-rc.4` unknown 1 CVE	Feb 22, 2022
`3.0.0-rc.3` unknown 1 CVE	Feb 16, 2022
`3.0.0-rc.2` unknown 1 CVE	Feb 08, 2022
`3.0.0-rc.1` unknown 1 CVE	Feb 01, 2022
`2.2.2` unknown 1 CVE	Jan 21, 2022
`3.0.0-beta.19` unknown 1 CVE	Jan 21, 2022
`3.0.0-beta.18` unknown 1 CVE	Jan 04, 2022
`3.0.0-beta.17` unknown 1 CVE	Dec 27, 2021
`3.0.0-beta.16` unknown 1 CVE	Dec 17, 2021
`3.0.0-beta.15` unknown 1 CVE	Dec 11, 2021
`3.0.0-beta.14` unknown 1 CVE	Nov 30, 2021
`3.0.0-beta.13` unknown 1 CVE	Nov 22, 2021
`3.0.0-beta.12` unknown 1 CVE	Nov 15, 2021
`3.0.0-beta.11` unknown 1 CVE	Oct 20, 2021
`3.0.0-beta.10` unknown 1 CVE	Sep 09, 2021
`3.0.0-beta.9` unknown 1 CVE	Aug 09, 2021
`2.2.1` unknown 1 CVE	Aug 09, 2021
`3.0.0-beta.8` unknown 1 CVE	Jun 26, 2021
`3.0.0-beta.7` unknown 1 CVE	Jun 19, 2021
`3.0.0-beta.6` unknown 1 CVE	Apr 17, 2021

3.13.5 patch

Sep 02, 2026

3.13.4 patch

Sep 02, 2026

3.13.3 patch

Aug 09, 2026

3.13.2 patch

Aug 07, 2026

3.13.1 unknown

Jun 22, 2026

3.13.0 unknown

Jun 21, 2026

3.12.1 unknown

Apr 18, 2026

3.12.0 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Feb 18, 2026

3.11.2 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Oct 05, 2025

3.11.1 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Aug 26, 2025

3.11.0 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

May 10, 2025

3.10.0 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Mar 10, 2025

3.9.0 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Aug 10, 2024

3.8.0 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Jun 19, 2024

3.7.0 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

May 19, 2024

3.6.0 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Feb 04, 2024

3.5.1 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Dec 25, 2023

3.5.0 unknown yanked

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Dec 24, 2023

3.4.0 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Aug 29, 2023

3.3.1 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Mar 02, 2023

3.3.0 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Jan 21, 2023

3.2.2 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Sep 11, 2022

3.2.1 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Jul 02, 2022

3.2.0 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Jul 01, 2022

3.1.0 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Jun 11, 2022

3.0.4 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Mar 09, 2022

3.0.3 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Mar 08, 2022

3.0.2 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Mar 05, 2022

3.0.1 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Mar 04, 2022

3.0.0 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Feb 25, 2022

3.0.0-rc.4 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Feb 22, 2022

3.0.0-rc.3 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Feb 16, 2022

3.0.0-rc.2 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Feb 08, 2022

3.0.0-rc.1 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Feb 01, 2022

2.2.2 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Jan 21, 2022

3.0.0-beta.19 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Jan 21, 2022

3.0.0-beta.18 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Jan 04, 2022

3.0.0-beta.17 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Dec 27, 2021

3.0.0-beta.16 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Dec 17, 2021

3.0.0-beta.15 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Dec 11, 2021

3.0.0-beta.14 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Nov 30, 2021

3.0.0-beta.13 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Nov 22, 2021

3.0.0-beta.12 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Nov 15, 2021

3.0.0-beta.11 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Oct 20, 2021

3.0.0-beta.10 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Sep 09, 2021

3.0.0-beta.9 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Aug 09, 2021

2.2.1 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Aug 09, 2021

3.0.0-beta.8 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Jun 26, 2021

3.0.0-beta.7 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Jun 19, 2021

3.0.0-beta.6 unknown

1 CVE

CVE-2026-73051 GHSA-xhj4-vrgc-hr34 Apr 22, 2026

actix-http has HTTP/1.1 CL.TE Request Smuggling

Medium

Network Low None None

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length.

Severity

Medium. This is an HTTP request smuggling vulnerability that can be triggered over the network without application-level credentials. Exploitation requires a specific proxy topology: an upstream proxy, WAF, load balancer, or similar intermediary must use Content-Length framing while forwarding the conflicting Transfer-Encoding: chunked request to an Actix backend over a reused HTTP/1.1 connection.

Affected Versions

actix-http: versions up to and including 3.12.0

Description

HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked are ambiguous and must be rejected by recipients to avoid request smuggling.

Affected versions of actix-http accepted a request with a syntactically valid Content-Length header and Transfer-Encoding: chunked on the same HTTP/1.1 message. The parser then selected chunked decoding instead of rejecting the conflicting framing signals.

In a CL.TE proxy topology, an intermediary may treat bytes after the declared Content-Length body as part of the first request, while the Actix backend stops at the terminating chunk marker and parses the remaining bytes on the backend connection as a second HTTP request. This creates a backend-side request desynchronization primitive.

The issue is limited to HTTP/1.1 request parsing.

Impact

HTTP request smuggling

Attack Vector: Network, unauthenticated.
Effect: Backend request desynchronization with low integrity impact to requests processed by the vulnerable Actix service.
Scope: Actix services using affected actix-http versions behind an HTTP/1.1 intermediary that forwards ambiguous Content-Length plus Transfer-Encoding: chunked requests and reuses backend connections.

No direct confidentiality, availability, or subsequent-system impact is scored for this advisory.

Fixed Versions

This issue is fixed in actix-http 3.12.1.

The fix rejects HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding: chunked instead of choosing one framing interpretation.

Mitigation

Users should upgrade to actix-http 3.12.1 or later.

Applications that depend on actix-http through actix-web, awc, or another Actix crate should ensure dependency resolution selects actix-http 3.12.1 or later. For example:

cargo update -p actix-http

If an immediate upgrade is not possible, configure all upstream HTTP intermediaries to reject HTTP/1.1 requests that contain both Content-Length and Transfer-Encoding, and avoid forwarding ambiguous request framing to Actix backends.

Credits

Actix thanks mufeedvh who disclosed this issue through coordinated disclosure.

Fixed in


          3.12.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Apr 17, 2021

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