CVE-2026-53612
util-linux mount hook_owner TOCTOU allows local privilege escalation
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Awaiting Analysis | 3.1 | High7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.15% · top 96% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.0.
Weakness
Affected products
- affected >= 2.39, < 2.41.5
- affected >= 2.42, < 2.42.2
References (7)
- https://github.com/util-linux/util-linux/security/advisories/GHSA-g8wm-75wr-g2vh (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/util-linux/util-linux/commit/24da33905c7115c4cbccd0afb2a469804e96467a (opens in a new tab)x_refsource_MISC
- https://github.com/util-linux/util-linux/commit/722c96974dd4009a334e4aee556eedaab5fb94b4 (opens in a new tab)x_refsource_MISC
- https://github.com/util-linux/util-linux/commit/897a08c2b11dfa66975c3d24d63c7bf5f5be1a7c (opens in a new tab)x_refsource_MISC
- https://github.com/util-linux/util-linux/commit/d0c5adaeb3a3d823aba1377794de8f009b8152cc (opens in a new tab)x_refsource_MISC
- https://github.com/util-linux/util-linux/releases/tag/v2.41.5 (opens in a new tab)x_refsource_MISC
- https://github.com/util-linux/util-linux/releases/tag/v2.42.2 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-53612)Record last updated .