{"id":"DEBIAN-CVE-2026-85091","details":"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.","modified":"2026-09-10T08:47:28.988539200Z","published":"2026-09-03T13:06:20.573Z","upstream":["CVE-2026-85091"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-85091"}],"affected":[{"package":{"name":"zlib","ecosystem":"Debian:12","purl":"pkg:deb/debian/zlib?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:1.2.13.dfsg-1","1:1.2.13.dfsg-2","1:1.2.13.dfsg-3","1:1.3.dfsg+really1.3.1-1","1:1.3.dfsg+really1.3.1-2","1:1.3.dfsg+really1.3.1-3","1:1.3.dfsg+really1.3.2-1","1:1.3.dfsg+really1.3.2-2","1:1.3.dfsg+really1.3.2-3","1:1.3.dfsg-1","1:1.3.dfsg-2","1:1.3.dfsg-3","1:1.3.dfsg-3.1","1:1.3.dfsg-3.1~exp1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-85091.json"}},{"package":{"name":"zlib","ecosystem":"Debian:13","purl":"pkg:deb/debian/zlib?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:1.3.dfsg+really1.3.1-1","1:1.3.dfsg+really1.3.1-2","1:1.3.dfsg+really1.3.1-3","1:1.3.dfsg+really1.3.2-1","1:1.3.dfsg+really1.3.2-2","1:1.3.dfsg+really1.3.2-3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-85091.json"}},{"package":{"name":"zlib","ecosystem":"Debian:14","purl":"pkg:deb/debian/zlib?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:1.3.dfsg+really1.3.1-1","1:1.3.dfsg+really1.3.1-2","1:1.3.dfsg+really1.3.1-3","1:1.3.dfsg+really1.3.2-1","1:1.3.dfsg+really1.3.2-2","1:1.3.dfsg+really1.3.2-3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-85091.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}