{"id":"CVE-2026-63209","published":"2026-09-29T15:17:27.130","lastModified":"2026-09-29T17:17:08.843","description":"compress provides various compression algorithms. Prior to version 1.18.7, a signed integer overflow vulnerability in s2.NewDict() allows an attacker to bypass repeat index validation by supplying a dictionary with a uvarint-encoded repeat value exceeding MaxInt64. When Dict.Encode() is subsequently called, the overflowed negative repeat value causes an out-of-bounds memory access via unsafe.Pointer arithmetic, crashing the process with SIGSEGV. This issue has been patched in version 1.18.7.","cvssScore":7.5,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwes":["CWE-190","CWE-787"],"vendors":[],"products":[],"references":[{"url":"https://github.com/klauspost/compress/commit/539243b8823ee8f03e49969823d57c348c917536","tags":[]},{"url":"https://github.com/klauspost/compress/releases/tag/v1.18.7","tags":[]},{"url":"https://github.com/klauspost/compress/security/advisories/GHSA-259r-337f-4rfw","tags":[]},{"url":"https://github.com/klauspost/compress/security/advisories/GHSA-259r-337f-4rfw","tags":[]}],"exploitRefs":[{"url":"https://github.com/klauspost/compress/commit/539243b8823ee8f03e49969823d57c348c917536","tags":[]},{"url":"https://github.com/klauspost/compress/releases/tag/v1.18.7","tags":[]},{"url":"https://github.com/klauspost/compress/security/advisories/GHSA-259r-337f-4rfw","tags":[]},{"url":"https://github.com/klauspost/compress/security/advisories/GHSA-259r-337f-4rfw","tags":[]}],"hasPoc":true,"ai":null}