Vulnerability in Util-Linux
CVE-2026-53612
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.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Util-Linux — versions >= 2.39, < 2.41.5, >= 2.42, < 2.42.2
Weakness classification (CWE)
References
- github.com/util-linux/util-linux/security/advisories/GHSA-g8wm-75wr-g2vh
- github.com/util-linux/util-linux/commit/24da33905c7115c4cbccd0afb2a469804e96467a
- github.com/util-linux/util-linux/commit/722c96974dd4009a334e4aee556eedaab5fb94b4
- github.com/util-linux/util-linux/commit/897a08c2b11dfa66975c3d24d63c7bf5f5be1a7c
- github.com/util-linux/util-linux/commit/d0c5adaeb3a3d823aba1377794de8f009b8152cc
- github.com/util-linux/util-linux/releases/tag/v2.41.5
- github.com/util-linux/util-linux/releases/tag/v2.42.2
Frequently asked questions
- What is CVE-2026-53612?
- CVE-2026-53612 is a high-severity vulnerability in Util-Linux, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 7.0/10. Published 2026-10-14.
- How severe is CVE-2026-53612?
- High severity. CVSS v3 base score is 7.0 out of 10.