CVE-2026-85091

A flaw was found in zlib. A heap buffer overflow vulnerability exists in the gzvacate function. This flaw can be triggered by a remote attacker calling gzprintf or gzvprintf after a write stall during non-blocking gzwrite operations with stale external buffer pointers. Successful exploitation cou...

CVE-2026-85091

zlib 1.2.11 through 1.3.2 contains a heap buffer overflow: after an underlying write fails, gzwrite returns without resetting strm.nextin, 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...

CVE-2026-85091

zlib versions 1.3.1.2 through 1.3.2 contain a heap buffer overflow vulnerability in the gzvacate 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...

CVE-2026-85091: Out-of-bounds Write

zlib versions 1.3.1.2 through 1.3.2 contain a heap buffer overflow vulnerability in the gzvacate 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...

PT-2026-90900

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...

CVE-2026-85091: Out-of-bounds Write

zlib versions 1.3.1.2 through 1.3.2 contain a heap buffer overflow vulnerability in the gzvacate 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...

PT-2026-90897

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...

PT-2026-90899

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...

PT-2026-90901

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...

PT-2026-90898

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...

Heap-based Buffer Overflow

Overview Affected versions of this package are vulnerable to Heap-based Buffer Overflow in the gzvprintf and gzprintf functions in gzwrite.c, where the fallback path selected by the NOvsnprintf and NOsnprintf macros formats into the internal state-in buffer with vsprintf or sprintf and performs n...