CVE-2026-41991

A flaw was found in the gzexe utility of GNU gzip. When the mktemp utility is not available, gzexe creates temporary files with predictable names based on the process ID. A local attacker can exploit this by pre-creating a symbolic link to an arbitrary file at the predicted temporary file path. This can lead to a Time-of-Check to Time-of-Use (TOCTOU) condition, allowing the attacker to overwrite arbitrary files on the system.

A flaw was found in the gzexe utility of GNU gzip. When the mktemp utility is not available in the user's PATH, gzexe creates temporary files with predictable names based on the process ID. A local attacker can exploit this by creating a symbolic link at the predicted temporary file path, leading to a TOCTOU race condition that allows arbitrary file overwrite. On Red Hat Enterprise Linux, mktemp is provided by coreutils which is always installed, making the vulnerable fallback code path effectively unreachable in standard deployments.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Ensure that the mktemp utility (provided by the coreutils package) is available in PATH when using the gzexe utility. On Red Hat Enterprise Linux, mktemp is installed by default and no additional action is needed.