Description
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.
Affected products
zlib: zlib
References9
- github.com/madler/zlib Product
- seclists.org/fulldisclosure/2026/Jan/3 Mailing ListThird Party Advisory
- www.vulncheck.com/advisories/zlib-untgz-global-buffer-overflow-… Third Party Advisory
- zlib.net/ Product
- github.com/madler/zlib/issues/1142 Issue Tracking
- access.redhat.com/security/cve/CVE-2026-22184
- bugzilla.redhat.com/show_bug.cgi?id=2427688
- cert-portal.siemens.com/productcert/html/ssa-470355.html
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-22184…
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 4.0
-
4.6
MEDIUM
Score source: CNA
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:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 36 · as of 11 November 2026
- CWE
- CWE-787CWE-120
Could this be exploited in your environment?
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