VULNERABILITY INTELLIGENCE
CVE-2026-76844
CVSS score7.4 HIGH
EPSS probability0.59%
CISA KEVNot currently listed
Published2026-08-24
Last modified2026-10-12
CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H
Description
zlib 1.2.11 through 1.3.2 contains a heap buffer overflow: after an underlying write() fails, gz_write() returns without resetting strm.next_in, leaving it pointed at the caller's buffer. A later gz* write call then derives a position from the stale pointer and writes past a heap allocation; any write() failure reaches it, including EPIPE on a blocking descriptor, and in versions before 1.3.1.2 the failed write must be followed by a gzclearerr() call.
Weakness classification
- disclosure@vulncheck.com: CWE-787