VULNERABILITY INTELLIGENCE
CVE-2026-85091
CVSS score7.4 HIGH
EPSS probability0.47%
CISA KEVNot currently listed
Published2026-09-03
Last modified2026-09-09
CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H
Description
zlib versions 1.3.1.2 through 1.3.2 contain a heap buffer overflow vulnerability in the gz_vacate() function when processing non-blocking gzwrite() operations with stale external buffer pointers. Attackers can trigger the overflow by calling gzprintf() or gzvprintf() after a write stall, causing an unchecked memmove() to write beyond the internal input buffer boundary.
Weakness classification
- disclosure@vulncheck.com: CWE-787