Reliance on Untrusted Inputs in a Security Decision in Util-linux - CVE-2026-53614

Vulnerability identifier: #VU146716

CSH Severity: Low

CVSS v4: 7.3 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-53614

CWE-ID: CWE-807

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to escalate privileges.

The vulnerability exists due to reliance on untrusted environment variables in libmount mount path selection when processing the LIBMOUNT_FORCE_MOUNT2 environment variable in the SUID mount(8) binary. A local user can set LIBMOUNT_FORCE_MOUNT2=always and trigger concurrent mount operations to escalate privileges.

Exploitation requires an /etc/fstab bind entry with user, nosuid, and noexec options where the bind source contains a SUID root binary.

Util-linux
openEuler
Fedora
libmount
python3-libmount
util-linux-debuginfo
util-linux-debugsource
util-linux-devel
util-linux-user
uuidd
util-linux-help
util-linux
libblkid
libfdisk
libuuid
libsmartcols

Install security update from vendor's website.

Util-linux - addressed in versions 2.41.5, 2.42.2
libmount - update to 2.39.1-44
python3-libmount - update to 2.39.1-44
util-linux-debuginfo - update to 2.39.1-44
util-linux-debugsource - update to 2.39.1-44
util-linux-devel - update to 2.39.1-44
util-linux-user - update to 2.39.1-44
uuidd - update to 2.39.1-44
util-linux-help - update to 2.39.1-44
util-linux - update to 2.39.1-44
libblkid - update to 2.39.1-44
libfdisk - update to 2.39.1-44
libuuid - update to 2.39.1-44
libsmartcols - update to 2.39.1-44
util-linux - addressed in versions 2.41.5-1.fc43, 2.41.5-1.fc44

• https://github.com/util-linux/util-linux/security/advisories/GHSA-67r7-8m5w-22wx
• https://github.com/util-linux/util-linux/commit/fd6b4d94ff013dc7ed680d4e864610da5b9751f1

• Fedora 44 update for util-linux
• Fedora 43 update for util-linux
• Multiple vulnerabilities in Util-linux
• openEuler 24.03 LTS SP3 update for util-linux
• openEuler 24.03 LTS SP1 update for util-linux
• openEuler 24.03 LTS SP4 update for util-linux