CVE-2026-22184
zlib <= 1.3.1.2 untgz Global Buffer Overflow in TGZfname()
MEDIUM 4.6EPSS 0.4%
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
- zlib software · zlib
- CVSS v4.0 VULNCHECK
- 4.6 MEDIUM
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 - CVSS v3.1 NVD
- 7.8 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS v3.1 CNA
- 8.6 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H - EPSS
- 0.41% chance of exploitation in the next 30 days, 34th percentile
- Published
- 2026-01-07
- Updated
- 2026-08-21
Proof-of-concept exploits (1)
Security advisories
- https://www.vulncheck.com/advisories/zlib-untgz-global-buffer-overflow-in-tgzfname
- madler/zlib/issues/1142
- https://zlib.net