CVE-2026-41991
MediumCVSS 4.7Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
GNU gzip has a vulnerability in the gzexe utility related to insecure temporary file handling. When mktemp is not available in the user's PATH, gzexe creates a temporary file with a predictable name based solely on the PID, without exclusive access or existence checks. A local attacker can pre-create this path as a symlink to an arbitrary writable file, causing a TOCTOU condition that allows arbitrary file overwrite.
Risk Assessment
The risk is that a local attacker can overwrite arbitrary files on the system, potentially leading to privilege escalation, data corruption, or system compromise.
Recommendation
Immediately update GNU gzip to a version containing commit 4e6f8b24ab823146ab8776f0b7fe486ab34d4269. As a temporary workaround, ensure the mktemp utility is available in the PATH for all users.
Other vulnerabilities in GNU gzip
See all- CVE-2022-1271High
An arbitrary file write vulnerability in GNU gzip's zgrep utility allows an attacker to overwrite arbitrary files. When zgrep processes a crafted file name with multiple newlines, it can write selected content to any file. This is due to insufficient validation of filenames.
- CVE-2026-41992High
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. 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 trigger an out-of-bounds read in the LZH decoder.
Original NVD description (English source)
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
Vulnerability data from NVD (NIST) · CISA KEV · EPSS