{"cve":"CVE-2026-63209","nvd":{"published":"2026-09-29T15:17:27.130","modified":"2026-09-30T19:57:08.043","status":"Deferred","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-190","CWE-787"],"references":["https://github.com/klauspost/compress/commit/539243b8823ee8f03e49969823d57c348c917536","https://github.com/klauspost/compress/releases/tag/v1.18.7","https://github.com/klauspost/compress/security/advisories/GHSA-259r-337f-4rfw","https://github.com/klauspost/compress/security/advisories/GHSA-259r-337f-4rfw"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:48.555445741+00:00"},"epss":{"cve":"CVE-2026-63209","score":0.00501,"percentile":0.42605,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-259r-337f-4rfw","url":"https://osv.dev/vulnerability/GHSA-259r-337f-4rfw","summary":"Compress/s2: Integer Overflow or Wraparound and Out-of-bounds Write in compress","modified":"2026-10-20T14:45:03.782718646Z","packages":[{"ecosystem":"Go","name":"github.com/klauspost/compress","purl":"pkg:golang/github.com/klauspost/compress","ranges":["<1.18.7"],"fixed":["1.18.7"]}]},{"id":"GO-2026-5841","url":"https://osv.dev/vulnerability/GO-2026-5841","summary":"OOB read in github.com/klauspost/compress/s2","modified":"2026-09-30T03:55:34.839663968Z","packages":[{"ecosystem":"Go","name":"github.com/klauspost/compress","purl":"pkg:golang/github.com/klauspost/compress","ranges":[">=1.16.0 <1.18.7"],"fixed":["1.18.7"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}