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
{
"cna_assigner": "CERT-PL",
"cwe_ids": [
"CWE-377"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41991.json",
"unresolved_ranges": [
{
"extracted_events": [
{
"range": [
{
"last_affected": "1.14"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
}
]
}
]
}{
"extracted_events": [
{
"range": [
{
"fixed": "4e6f8b24ab823146ab8776f0b7fe486ab34d4269"
}
],
"source": "REFERENCES_COMMIT"
}
]
}