A AegiFlow
HIGHCVSS 7.5EPSS 0.4%

CVE-2026-63209

CVE-2026-63209 updated by NVD

Published
2026-10-20
Modified
2026-10-20
EPSS percentile
29%
Sources
github-advisory, nvd

Summary

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.

Affected packages

EcosystemPackageAffected versionsFixed versions
Gogithub.com/klauspost/compress—1.18.7

Remediation: Upgrade to 1.18.7 or later.

References

Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.

Includes data from the National Vulnerability Database (NIST). NVD data is in the public domain; this page is not endorsed by NIST.

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EPSS scores provided by the FIRST.org Exploit Prediction Scoring System.