CVE-2026-63209
Integer Overflow or Wraparound and Out-of-bounds Write in compress
- State
- Published
- Severity
- 7.5 High
- Published
- Sep 29, 2026
- Updated
- Sep 29, 2026
- Reserved
- Jul 15, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
compressklauspost |
|
References
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