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CVE-2026-53612

CVE-2026-53612 · util-linux mount hook_owner TOCTOU allows local privilege escalation

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

util-linux is a random collection of Linux utilities. In util-linux 2.39 through 2.41.4 and 2.42 through 2.42.1, the SUID `mount` utility's `hook_owner.c` post-mount hook performs path-based `chmod()` and `lchown()` operations on a previously validated mount target. A local low-privileged user authorized by an `/etc/fstab` entry with `user` or `users` and an `X-mount.mode`, `X-mount.owner`, or `X-mount.group` option can use `renameat2(RENAME_EXCHANGE)` to race a writable ancestor of the target and redirect the privileged ownership or mode change to a root-owned path, potentially gaining root privileges. This issue is fixed in 2.41.5 and 2.42.2.

CVSS 7.0 · High · EPSS 0.1% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • util-linux

    Versions
    • >= 2.39, < 2.41.5: Affected
    • >= 2.42, < 2.42.2: Affected

    No fix published

  • util-linux Debian:13

    Versions
    • 2.41-5
    • 2.41.1-1
    • 2.41.1-2
    • 2.41.1-3
    • 2.41.1-4
    • 2.41.2-1
    • 2.41.2-2
    • 2.41.2-3
    • 2.41.2-4
    • 2.41.3-1
    • 2.41.3-2
    • 2.41.3-3
    • 2.41.3-4
    Affected ranges
    • ECOSYSTEM: < 2.41.5-0+deb13u1

    Update to 2.41.5-0+deb13u1

  • util-linux Debian:14

    Versions
    • 2.41-5
    • 2.41.1-1
    • 2.41.1-2
    • 2.41.1-3
    • 2.41.1-4
    • 2.41.2-1
    • 2.41.2-2
    • 2.41.2-3
    • 2.41.2-4
    • 2.41.3-1
    • 2.41.3-2
    • 2.41.3-3
    • 2.41.3-4
    • 2.42-1
    • 2.42-2
    • 2.42-3
    • 2.42-4
    • 2.42-5
    • 2.42-6
    • 2.42.1-1
    • 2.42.1-2
    • 2.42.1-3
    • 2.42.1-4
    • 2.42.1-5
    • 2.42.1-6
    • 2.42~rc1-1
    • 2.42~rc1-2
    • 2.42~rc1-3
    • 2.42~rc2-1
    Affected ranges
    • ECOSYSTEM: < 2.42.2-1

    Update to 2.42.2-1

  • util-linux Ubuntu:24.04:LTS

    Versions
    • 2.39.1-4ubuntu2
    • 2.39.2-6ubuntu1
    • 2.39.3-6ubuntu2
    • 2.39.3-9ubuntu2
    • 2.39.3-9ubuntu4
    • 2.39.3-9ubuntu6
    • 2.39.3-9ubuntu6.1
    • 2.39.3-9ubuntu6.2
    • 2.39.3-9ubuntu6.3
    • 2.39.3-9ubuntu6.4
    • 2.39.3-9ubuntu6.5
    Affected ranges
    • ECOSYSTEM: < 2.39.3-9ubuntu6.6

    Update to 2.39.3-9ubuntu6.6

  • util-linux Ubuntu:25.10

    Versions
    • 2.40.2-14ubuntu1
    • 2.41-4ubuntu2
    • 2.41-4ubuntu3
    • 2.41-4ubuntu4
    • 2.41-4ubuntu4.1
    • 2.41-4ubuntu4.2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • util-linux Ubuntu:26.10

    Versions
    • 2.41.3-3ubuntu2
    • 2.42.2-1ubuntu2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • util-linux Ubuntu:26.04:LTS

    Versions
    • 2.41-4ubuntu4
    • 2.41.2-4ubuntu1
    • 2.41.2-4ubuntu2
    • 2.41.2-4ubuntu3
    • 2.41.3-3ubuntu1
    • 2.41.3-3ubuntu2
    Affected ranges
    • ECOSYSTEM: < 2.41.3-3ubuntu2.2

    Update to 2.41.3-3ubuntu2.2

Original sources

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