Vulnerability in Util-Linux
CVE-2026-53613
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.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
Published .
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 >= 2.17, <= 2.41.6, >= 2.42, <= 2.42.4
Weakness classification (CWE)
References
- github.com/util-linux/util-linux/security/advisories/GHSA-8gj5-72r3-428g
- github.com/util-linux/util-linux/commit/0b010025a0e429bc80355c94db86a843395d49e2
- github.com/util-linux/util-linux/commit/0d3d55975aa3492c62fd345eac38f41cd166c0b0
- github.com/util-linux/util-linux/commit/2c773f336134acf016e639abb6f12ba7341fe4b8
- github.com/util-linux/util-linux/commit/39fef62bf3226abb6bb018fa8750afa0327e84b4
- github.com/util-linux/util-linux/commit/472cc3fb2d4d47cca7aab2e0b59eb3fb8a9359ec
- github.com/util-linux/util-linux/commit/646fb66603d10a7ac337e14f566f1af48e3107c9
- github.com/util-linux/util-linux/commit/708d1b3c51932dc5ba8082c7368187715e6a8d78
- github.com/util-linux/util-linux/commit/78a860982e036f38fe9c0b3344998df5ac2c2ff5
- github.com/util-linux/util-linux/commit/85d16b341f7232c9dbb4884b632e1e956584bee9
Frequently asked questions
- What is CVE-2026-53613?
- CVE-2026-53613 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-2026-53613?
- High severity. CVSS v3 base score is 7.0 out of 10.