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CVE-2026-41991

CVE-2026-41991 · Predictable Temporary File in GNU gzip

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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

CVSS 2.0 · Low · EPSS 0.1% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • gzip

    Versions
    • ≥ 0, ≤ 1.14: Affected (semver)

    No fix published

  • gzip Debian:12

    Versions
    • 1.12-1
    • 1.12-1.1
    • 1.12-1.2
    • 1.13-1
    • 1.13.56~e549-1~exp1
    • 1.14-1
    • 1.14-1~exp1
    • 1.14-1~exp2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • gzip Debian:13

    Versions
    • 1.13-1
    Affected ranges
    • ECOSYSTEM: < 1.13-1+deb13u1

    Update to 1.13-1+deb13u1

  • gzip Debian:14

    Versions
    • 1.13-1
    • 1.13.56~e549-1~exp1
    • 1.14-1~exp1
    • 1.14-1~exp2
    Affected ranges
    • ECOSYSTEM: < 1.14-1

    Update to 1.14-1

  • gzip Ubuntu:Pro:14.04:LTS

    Versions
    • 1.6-2ubuntu1
    • 1.6-3ubuntu1
    • 1.6-3ubuntu1+esm1
    Affected ranges
    • ECOSYSTEM: < 1.6-3ubuntu1+esm2

    Update to 1.6-3ubuntu1+esm2

  • gzip Ubuntu:Pro:16.04:LTS

    Versions
    • 1.6-4ubuntu1
    • 1.6-4ubuntu1+esm1
    Affected ranges
    • ECOSYSTEM: < 1.6-4ubuntu1+esm2

    Update to 1.6-4ubuntu1+esm2

  • gzip Ubuntu:Pro:18.04:LTS

    Versions
    • 1.6-5ubuntu1
    • 1.6-5ubuntu1.1
    • 1.6-5ubuntu1.2
    Affected ranges
    • ECOSYSTEM: < 1.6-5ubuntu1.2+esm1

    Update to 1.6-5ubuntu1.2+esm1

  • gzip Ubuntu:Pro:20.04:LTS

    Versions
    • 1.10-0ubuntu3
    • 1.10-0ubuntu4
    • 1.10-0ubuntu4.1
    Affected ranges
    • ECOSYSTEM: < 1.10-0ubuntu4.1+esm1

    Update to 1.10-0ubuntu4.1+esm1

  • gzip Ubuntu:22.04:LTS

    Versions
    • 1.10-4ubuntu1
    • 1.10-4ubuntu2
    • 1.10-4ubuntu3
    • 1.10-4ubuntu4
    • 1.10-4ubuntu4.1
    Affected ranges
    • ECOSYSTEM: < 1.10-4ubuntu4.2

    Update to 1.10-4ubuntu4.2

  • gzip Ubuntu:24.04:LTS

    Versions
    • 1.12-1ubuntu1
    • 1.12-1ubuntu2
    • 1.12-1ubuntu3
    • 1.12-1ubuntu3.1
    Affected ranges
    • ECOSYSTEM: < 1.12-1ubuntu3.2

    Update to 1.12-1ubuntu3.2

  • gzip Ubuntu:25.10

    Versions
    • 1.13-1ubuntu3
    • 1.13-1ubuntu4
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • gzip Ubuntu:26.04:LTS

    Versions
    • 1.13-1ubuntu4
    • 1.13-1ubuntu5
    • 1.14-1~exp2ubuntu1
    Affected ranges
    • ECOSYSTEM: < 1.14-1~exp2ubuntu1.1

    Update to 1.14-1~exp2ubuntu1.1

Original sources

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