CVE-2026-41992: GNU gzip · Buffer Over-read
Affects GNU gzipSource CVE Database V5
Not known to be exploited · CVSS 6.9 Medium.
Data as of 10 Nov 2026, 23:24 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 50% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 29 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| GNUgzip | Affected
| Fixed in– |
AI-suggested
A fix for this vulnerability has been implemented in the referenced commit (63dbf6b3b9e6e781df1a6a64e609b10e23969681). Users should update to a version of GNU gzip that includes this fix. Patch status is not explicitly stated beyond the commit; therefore, verify with the official GNU gzip source or vendor advisory for the availability of updated releases containing this fix.
Description
GNU gzip contains a global buffer overflow vulnerability in the LZH decompression logic caused by improper reuse of shared global state between different decompression formats within a single execution. GNU gzip maintains a global array that is shared across the LZ77, LZW, and LZH decompression routines and is not reinitialized between files processed in the same invocation. By decompressing a specially crafted LZW file followed by a specially crafted LZH file in a single gzip -d command, an attacker can poison the shared global state and subsequently trigger an out‑of‑bounds read in the LZH decoder. The LZH decompression logic follows stale values left in the shared array, causing reads past the end of the allocated global buffer. This issue has been fixed in commits 63dbf6b3b9e6e781df1a6a64e609b10e23969681 and e7378c2d421be6a286922374425680bbe9ad8b7d.
References
- cert.pl/en/posts/2026/04/CVE-2026-41991/ (opens in a new tab)
- gnu.org/software/gzip/ (opens in a new tab)
- cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=63dbf6b3b9e6e781df1a6a64e609b10e23969681 (opens in a new tab)
- openwall.com/lists/oss-security/2026/08/23/1 (opens in a new tab)
- openwall.com/lists/oss-security/2026/08/25/1 (opens in a new tab)
- openwall.com/lists/oss-security/2026/08/27/2 (opens in a new tab)
- cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=e7378c2d421be6a286922374425680bbe9ad8b7d (opens in a new tab)