CVE-2026-53613
util-linux mount target TOCTOU allows local privilege escalation
- State
- Published
- Severity
- 7.0 High
- Published
- Oct 14, 2026
- Updated
- Oct 15, 2026
- Reserved
- Jun 9, 2026
Description
util-linux is a random collection of Linux utilities. In util-linux 2.17 through 2.41.6 and 2.42 through 2.42.3, and in 2.42.4 when the legacy `mount(2)` path is used without `/proc`, restricted non-root `mount` requests validate an `/etc/fstab` target before the mount operation re-resolves that pathname. A local low-privileged user authorized by an fstab `user` or `users` entry whose target has an attacker-writable ancestor can use `renameat2(RENAME_EXCHANGE)` to swap a path component and redirect an authorized mount to a root-owned location, such as mounting attacker-controlled content over `/etc/sudoers.d`, and thereby gain root privileges. Versions 2.41.5 and 2.42.2 pin targets for the new mount API, and 2.42.4 pins legacy targets through `/proc/self/fd`; the documented legacy fallback without `/proc` remains affected.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.0 High | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H | GitHub_M |
Weaknesses
- CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
Affected Products
| Product | Versions |
|---|---|
util-linuxutil-linux |
|
References
- https://github.com/util-linux/util-linux/security/advisories/GHSA-8gj5-72r3-428g
- https://github.com/util-linux/util-linux/commit/0b010025a0e429bc80355c94db86a843395d49e2
- https://github.com/util-linux/util-linux/commit/0d3d55975aa3492c62fd345eac38f41cd166c0b0
- https://github.com/util-linux/util-linux/commit/2c773f336134acf016e639abb6f12ba7341fe4b8
- https://github.com/util-linux/util-linux/commit/39fef62bf3226abb6bb018fa8750afa0327e84b4
- https://github.com/util-linux/util-linux/commit/472cc3fb2d4d47cca7aab2e0b59eb3fb8a9359ec
- https://github.com/util-linux/util-linux/commit/646fb66603d10a7ac337e14f566f1af48e3107c9
- https://github.com/util-linux/util-linux/commit/708d1b3c51932dc5ba8082c7368187715e6a8d78
- https://github.com/util-linux/util-linux/commit/78a860982e036f38fe9c0b3344998df5ac2c2ff5
- https://github.com/util-linux/util-linux/commit/85d16b341f7232c9dbb4884b632e1e956584bee9
- https://github.com/util-linux/util-linux/commit/a9508d216eb8977979102782672e0470cc9bf2a2
- https://github.com/util-linux/util-linux/releases/tag/v2.41.5
- https://github.com/util-linux/util-linux/releases/tag/v2.42.2
- https://github.com/util-linux/util-linux/releases/tag/v2.42.4
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.