{"id":"CVE-2026-76844","revision":"eebbb31f323446c6bac2fa44efc01122","records":[{"revision":"eebbb31f323446c6bac2fa44efc01122","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-76844","aliases":[],"title":"zlib 1.2.11 through 1.3.2 Heap Buffer Overflow via Stale gzwrite Pointer After Failed Write","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.","state":0,"publishedAt":"2026-08-24T13:12:01.148+00:00","modifiedAt":"2026-10-01T11:03:59.221+00:00","affected":[{"ecosystem":"Vendor product","name":"zlib","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"zlib\",\n                    \"product\": \"zlib\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"packageURL\": \"pkg:github/madler/zlib\",\n                    \"versions\": [\n                        {\n                            \"version\": \"1.2.11\",\n                            \"lessThanOrEqual\": \"1.3.2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"custom\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N","score":8.3,"severity":"HIGH"},{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H","score":7.4,"severity":"HIGH"}],"references":["https://gist.github.com/thesmartshadow/e0b9481792afb7c31e86fee1ff084490","https://github.com/madler/zlib/commit/df84af25dc1942490e1d1c899a07619152a46148","https://github.com/madler/zlib/blob/v1.3.2/gzwrite.c#L393","https://github.com/madler/zlib","https://www.vulncheck.com/advisories/zlib-1.3.1.2-through-1.3.2-heap-buffer-overflow-via-gz-vacate"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-76844","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-76844","identifiers":["CVE-2026-76844"]},"retained":false,"historicalAffected":[]}],"coverage":[]}