Vulnerability · Published Jun 29, 2026 · Assigned by CERT-PL
CVE-2026-41992Global Buffer Overflow in GNU gzip
Medium 6.9
In plain English
A medium-severity security flaw in gzip from GNU. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | gzip | 1.13-4.el10_2 | ALSA-2026:61625 |
| AlmaLinux:8 | gzip | 1.9-15.el8_10 | ALSA-2026:65998 |
| AlmaLinux:9 | gzip | 1.12-2.el9_8 | ALSA-2026:61623 |
| Alpine:v3.21 | gzip | 1.13-r1 | ALPINE-CVE-2026-41992 |
| Alpine:v3.22 | gzip | 1.14-r2 | ALPINE-CVE-2026-41992 |
| Alpine:v3.23 | gzip | 1.14-r3 | ALPINE-CVE-2026-41992 |
| Alpine:v3.24 | gzip | 1.14-r3 | ALPINE-CVE-2026-41992 |
| Debian:12 | gzip | no fix listed | DEBIAN-CVE-2026-41992 |
| Debian:13 | gzip | 1.13-1+deb13u1 | DEBIAN-CVE-2026-41992 |
| Debian:14 | gzip | 1.14-1 | DEBIAN-CVE-2026-41992 |
| Rocky Linux:10 | gzip | 0:1.13-4.el10_2 | RLSA-2026:61625 |
| Rocky Linux:8 | gzip | 0:1.9-15.el8_10 | RLSA-2026:65998 |
| Rocky Linux:9 | gzip | 0:1.12-2.el9_8 | RLSA-2026:61623 |
| Ubuntu:22.04:LTS | gzip | 1.10-4ubuntu4.2 | UBUNTU-CVE-2026-41992 |
| Ubuntu:22.04:LTS | gzip | 1.10-4ubuntu4.2 | USN-8512-1 |
| Ubuntu:24.04:LTS | gzip | 1.12-1ubuntu3.2 | UBUNTU-CVE-2026-41992 |
| Ubuntu:24.04:LTS | gzip | 1.12-1ubuntu3.2 | USN-8512-1 |
| Ubuntu:25.10 | gzip | no fix listed | UBUNTU-CVE-2026-41992 |
| Ubuntu:26.04:LTS | gzip | 1.14-1~exp2ubuntu1.1 | UBUNTU-CVE-2026-41992 |
| Ubuntu:26.04:LTS | gzip | 1.14-1~exp2ubuntu1.1 | USN-8512-1 |
Affected products (as reported)
Weakness: CWE-126 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
References
- https://cert.pl/en/posts/2026/04/CVE-2026-41991/ third-party-advisory
- https://www.gnu.org/software/gzip/ product
- https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=63dbf6b3b9e6e781df1a6a64e609b10e23969681 patch
- https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=e7378c2d421be6a286922374425680bbe9ad8b7d patch
- http://www.openwall.com/lists/oss-security/2026/08/23/1
- http://www.openwall.com/lists/oss-security/2026/08/25/1
- http://www.openwall.com/lists/oss-security/2026/08/27/2