High severity · published Oct 14, 2026
CVE-2026-53613
util-linux mount target TOCTOU allows local privilege escalation
7.0
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
High
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 5% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
UT
util-linux · util-linux
>= 2.17, <= 2.41.6; >= 2.42, <= 2.42.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-53613
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-53613
x_refsource_CONFIRM
https://github.com/util-linux/util-linux/security/advisories/GHSA-8gj5-72r3-428g
x_refsource_MISC
https://github.com/util-linux/util-linux/commit/0b010025a0e429bc80355c94db86a843395d49e2
x_refsource_MISC
https://github.com/util-linux/util-linux/commit/0d3d55975aa3492c62fd345eac38f41cd166c0b0
x_refsource_MISC
https://github.com/util-linux/util-linux/commit/2c773f336134acf016e639abb6f12ba7341fe4b8
x_refsource_MISC
https://github.com/util-linux/util-linux/commit/39fef62bf3226abb6bb018fa8750afa0327e84b4
x_refsource_MISC
https://github.com/util-linux/util-linux/commit/472cc3fb2d4d47cca7aab2e0b59eb3fb8a9359ec
More from util-linux
8.0
CVE-2026-53615
util-linux libblkid DOS extended-partition overflow produces invalid partition metadata
7.8
CVE-2026-76642
util-linux libmount Privilege Escalation via Failed Mount Helper
7.0
CVE-2026-53614
util-linux LIBMOUNT_FORCE_MOUNT2 allows nosuid and noexec bypass
7.0
CVE-2026-53612
util-linux mount hook_owner TOCTOU allows local privilege escalation
6.1
CVE-2025-14104
Util-linux: util-linux: heap buffer overread in setpwnam() when processing 256-byte usernames
