USN-8733-2: Gzip vulnerabilities
Ubuntu patches Gzip vulnerabilities (CVE-2026-41991) in USN-8733-2 for LTS versions, addressing insecure temp files and incorrect handling of compressed files.
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CVE-2026-41991
- CVSS 4.0
- 2.0 low
- EPSS
- <1%p8
- Published
- ·
- Modified
Description · NVD
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
- Vendors
- gnu
- Products
- gzip
- Weakness
- CWE-377
- Vector
- CVSS:4.0/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
In the news
2 storiesUSN-8733-1: Gzip vulnerabilities
Ubuntu issued USN-8733-1 fixing two Gzip flaws: insecure gzexe temp files allowing file overwrites, and a crafted-file DoS/info exposure bug.
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