Vulnerability record · CVE-2026-22184 · published 7 January 2026

CVE-2026-22184: Zlib out-of-bounds write vulnerability

Zlib · Zlib

zlib versions up to and including 1.3.1.2 include a global buffer overflow in the untgz utility located under contrib/untgz. The vulnerability is limited to the standalone demonstration utility and does not affect the core zlib compression library. The flaw occurs when a user executes the untgz command with an excessively long archive name supplied via the command line, leading to an out-of-bounds write in a fixed-size global buffer.

4.6 CVSS 4.0 Medium EPSS 0.42% · top 66.3% CWE-787 · Out-of-bounds writeCWE-120 · Classic buffer overflow

4.6CVSS 4.0 base score

0.42%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

9References

1 Sep 2026Last modified by NVD

Description

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:L/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:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

Zlib Zlib

References

Link	Tags
https://github.com/madler/zlib	Product
https://seclists.org/fulldisclosure/2026/Jan/3	Mailing ListThird Party Advisory
https://www.vulncheck.com/advisories/zlib-untgz-global-buffer-overflow-in-tgzfname	Third Party Advisory
https://zlib.net/	Product
https://github.com/madler/zlib/issues/1142	Issue Tracking
https://access.redhat.com/security/cve/CVE-2026-22184
https://bugzilla.redhat.com/show_bug.cgi?id=2427688
https://cert-portal.siemens.com/productcert/html/ssa-470355.html
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-22184.json

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-22184), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.