Read the docs
TI-2026-73995 Aliases CVE-2026-53613

Race condition in util-linux mount lets local users gain root

Priority LOW 32CWE-367Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 4 fixed, 6 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

util-linux from 2.17 through 2.41.6 and from 2.42 through 2.42.4 is affected, including 2.42.4 when the legacy mount(2) path is used without /proc. The mount utility checks an /etc/fstab target before it re-resolves the path, a time-of-check to time-of-use race (CWE-367). A local user with low privileges who is authorized by an fstab user or users entry can swap a path component so that an authorized mount lands in a root-owned location, such as /etc/sudoers.d, and gain root privileges.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00163 5th percentileScored 2026-11-07
Fix Partial Red Hat: 2 advisoriesRed Hat: 4 fixed, 6 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
util-linuxutil-linux2.17 – 2.41.6; 2.42 – 2.42.4—No fix listedCNA
  • util-linux Vendorutil-linux Affected 2.17 – 2.41.6; 2.42 – 2.42.4 Fixed in — No fix listed CNA

Remediation

Red Hat fixes Red Hat Enterprise Linux AppStream, BaseOS and CodeReady Linux Builder version 10 in RHSA-2026:93461, and Red Hat Cost Management On-Premise 1 in RHSA-2026:95365. The sources list no fixed version for util-linux or Red Hat OpenShift AI (RHOAI). Red Hat Enterprise Linux 7, 8 and 9 and Red Hat OpenShift Container Platform 4 and 5 have no fix available.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Red Hat 2 advisories

  • RHSA-2026:95365 Released 2026-11-04 · Red Hat rating Critical
    Red Hat Cost Management On-Premise container image update
    • Red Hat Cost Management On-Premise 1 registry.redhat.io/costmanagement/costmanagement-ui-rhel10
  • RHSA-2026:93461 Released 2026-11-02 · Red Hat rating Important
    util-linux security update
    • Red Hat Enterprise Linux AppStream (v. 10) libblkid-devel-2.40.2-18.el10_2.20, libmount-devel-2.40.2-18.el10_2.20, libuuid-devel-2.40.2-18.el10_2.20 +2
    • Red Hat Enterprise Linux BaseOS (v. 10) libblkid-2.40.2-18.el10_2.20, libfdisk-2.40.2-18.el10_2.20, libmount-2.40.2-18.el10_2.20 +4
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libfdisk-devel-2.40.2-18.el10_2.20, libsmartcols-devel-2.40.2-18.el10_2.20

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat Enterprise Linux 8AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat OpenShift AI (RHOAI)Affected—
Red Hat OpenShift Container Platform 4AffectedNo fix yet
Red Hat OpenShift Container Platform 5AffectedNo fix yet
Red Hat Cost Management On-Premise 1Fixed RHSA-2026:95365
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:93461
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:93461
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:93461
Not affected: 2 products
  • Red Hat Hardened Images
  • Red Hat OpenShift AI (RHOAI)

Timeline

  1. 2026-10-14 Threatist record created from CVE-2026-53613
  2. 2026-10-16 CISA SSVC decision points changed
  3. 2026-10-16 Priority changed: MEDIUM → LOW
  4. 2026-10-30 Affected versions changed · Red Hat
  5. 2026-11-02 Fix available: RHSA-2026:93461 · Red Hat
  6. 2026-11-02 Fix available: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · Red Hat
  7. 2026-11-05 Fix available: Red Hat Cost Management On-Premise 1 · Red Hat
  8. 2026-11-06 Fix available: RHSA-2026:95365 · Red Hat
  9. 2026-11-06 Affected versions changed · Red Hat

References

Other 14

  • TI-2026-53553 util-linux libmount Privilege Escalation via Failed Mount Helper CVSS 4.0HIGH 8.5
  • TI-2026-73994 Race condition in util-linux mount hook allows privilege escalation CVSS 3.1HIGH 7.0
  • TI-2026-74163 Integer overflow in util-linux libblkid DOS extended partition parsing CVSS 3.1HIGH 8.0
  • TI-2026-73996 util-linux LIBMOUNT_FORCE_MOUNT2 allows nosuid and noexec bypass CVSS 3.1HIGH 7.0
  • TI-2025-12886 Util-linux: util-linux: heap buffer overread in setpwnam() when processing 256-byte usernames CVSS 3.1MEDIUM 6.1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences