CVE-2026-41991
GNU gzip contains a vulnerability in the gzexe utility related to insecure temporary file handling. When the mktemp utility is not available in the user’s PATH, gzexe falls back to constructing a temporary file path based solely on the process ID (PID). This predictable filename is created without exclusive access or existence checks. A local attacker can pre‑create the predicted temporary file path as a symbolic link pointing to an arbitrary file writable by the victim. When gzexe runs, it follows the symlink and overwrites the target file, resulting in a time‑of‑check to time‑of‑use (TOCTOU) condition that allows arbitrary file overwrite. This issue has been fixed in the commit 4e6f8b24ab823146ab8776f0b7fe486ab34d4269
- Score
- CVSS 3.1 4.7 Medium
- Status
- Analyzed - cvd@cert.pl
- Published
- 2026-06-29
- Last modified
- 2026-10-25
- Weaknesses
- CWE-377
Affected products
References
- https://cert.pl/en/posts/2026/04/CVE-2026-41991/
- https://www.gnu.org/software/gzip/
- https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=4e6f8b24ab823146ab8776f0b7fe486ab34d4269
