CVE-2026-63209 — Integer Overflow or Wraparound and Out-of-bounds Write in compress
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 vali…
Published: 2026-09-29 · CVSS: 7.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7