PT-2026-53255 · Gnu · Gzip

Marcin Wyczechowski + 1 · Published 2026-06-29 · Updated 2026-06-29 · CVE-2026-41991

NVD

CVSS v4.0

2.0

Low

Base vector

AV:L/AC:H/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/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

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

Fix

Weakness Enumeration

CWE-377

Related Identifiers

CVE-2026-41991

Affected Products

Gzip

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-41991 · Security Note
• https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=4e6f8b24ab823146ab8776f0b7fe486ab34d4269 · Patch
• https://gnu.org/software/gzip · Note
• https://cert.pl/en/posts/2026/04/CVE-2026-41991 · Note