CVE-2026-41991

Publication date 29 June 2026

Last updated 6 July 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

4.7 · Medium

Score breakdown

Description

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

Status

Package Ubuntu Release Status
gzip 26.04 LTS resolute
Fixed 1.14-1~exp2ubuntu1.1
25.10 questing
Needs evaluation
24.04 LTS noble
Fixed 1.12-1ubuntu3.2
22.04 LTS jammy
Fixed 1.10-4ubuntu4.2
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty
Needs evaluation

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
gzip

Severity score breakdown

CVSS version:

Base score 2.0 · Low

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

Base score 4.7 · Medium

Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N

References

Related Ubuntu Security Notices (USN)

Other references

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