CVE-2026-85091

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Source
https://cve.org/CVERecord?id=CVE-2026-85091
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-85091.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-85091
Downstream
Published
2026-09-03T01:04:44.460Z
Modified
2026-09-04T03:30:48.590325984Z
Severity
  • 8.3 (High) CVSS_V4 - 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 CVSS Calculator
Summary
zlib 1.3.1.2 through 1.3.2 Heap Buffer Overflow via gz_vacate
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.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/85xxx/CVE-2026-85091.json",
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
        "CWE-787"
    ]
}
References

Affected packages

Git / github.com/madler/zlib

Affected ranges

Type
GIT
Repo
https://github.com/madler/zlib
Events
Introduced
570720b0c24f9686c33f35a1b3165c1f568b96be
Last affected
da607da739fa6047df13e66a2af6b8bec7c2a498
Database specific
Show details 
{
    "source": "AFFECTED_FIELD",
    "extracted_events": [
        {
            "introduced": "1.3.1.2"
        },
        {
            "last_affected": "1.3.2"
        }
    ]
}

Affected versions

v1.*
v1.3.1.2
v1.3.2

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-85091.json"