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.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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. (CVE-2026-85091)

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2026-85091)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
473477	Alpine: multiple zlib packages: security update to 1.3.2-r1	Tenable Cloud Security	Alpine Linux Local Security Checks	Local	high
473477	Alpine: multiple zlib packages: security update to 1.3.2-r1	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	Local	high
461804	Echo: zlib: security update to 1:1.3.dfsg+really1.3.1-1+e2	Tenable Cloud Security	Echo Local Security Checks	Local	high
461804	Echo: zlib: security update to 1:1.3.dfsg+really1.3.1-1+e2	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	high
342781	Linux Distros Unpatched Vulnerability : CVE-2026-85091	Nessus	Misc.	Local	high

Detections

Analytics

CVE-2026-85091

high

Tenable Plugins

high

high

high

high

high