EUVD-2026-319281

fkie_cve-2026-44302

Snappier is a high performance C# implementation of the Snappy compression algorithm. Prior to 1.3.1, Snappier.SnappyStream enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes. This vulnerability is fixed in 1.3.1.

GHSA-pggp-6c3x-2xmx — Snappier has an infinite loop during SnappyStream decompression with malformed framed input

Affected: NuGet: Snappier

### 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 ```csharp 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).

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EUVD-2026-319281

fkie_cve-2026-44302

GHSA-pggp-6c3x-2xmx — Snappier has an infinite loop during SnappyStream decompression with malformed framed input