---
id: CVE-2026-27456
title: util-linux is a random collection of Linux utilities
summary: >-
  util-linux is a random collection of Linux utilities. Prior to version 2.41.4,
  a TOCTOU (Time-of-Check-Time-of-Use) vulnerability has been identified in the
  SUID binary /usr/bin/mount from util-linux. The mount binary, when setting up
  lo…
severity: medium
cvss: 4.7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-59
  - CWE-269
  - CWE-367
vendor: kernel
product: util-linux
affected:
  - util-linux < 2.41.4
patched:
  - util-linux 2.41.4
published: '2026-04-03'
updated: '2026-07-24'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-27456'
references:
  - url: >-
      https://github.com/util-linux/util-linux/commit/5e390467b26a3cf3fecc04e1a0d482dff3162fc4
    label: security-advisories@github.com
  - url: 'https://github.com/util-linux/util-linux/releases/tag/v2.41.4'
    label: security-advisories@github.com
  - url: >-
      https://github.com/util-linux/util-linux/security/advisories/GHSA-qq4x-vfq4-9h9g
    label: security-advisories@github.com
  - url: >-
      https://github.com/util-linux/util-linux/security/advisories/GHSA-qq4x-vfq4-9h9g
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27456.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-27456'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2454956'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-27456'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-27456'
  - url: 'https://access.redhat.com/errata/RHSA-2026:7180'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
epss: 0.00118
epssPercentile: 0.01525
ingestedAt: '2026-07-25T22:05:05.013Z'
---

## Overview

util-linux is a random collection of Linux utilities. Prior to version 2.41.4, a TOCTOU (Time-of-Check-Time-of-Use) vulnerability has been identified in the SUID binary /usr/bin/mount from util-linux. The mount binary, when setting up loop devices, validates the source file path with user privileges via fork() + setuid() + realpath(), but subsequently re-canonicalizes and opens it with root privileges (euid=0) without verifying that the path has not been replaced between both operations. Neither O_NOFOLLOW, nor inode comparison, nor post-open fstat() are employed. This allows a local unprivileged user to replace the source file with a symlink pointing to any root-owned file or device during the race window, causing the SUID binary to open and mount it as root. Exploitation requires an /etc/fstab entry with user,loop options whose path points to a directory where the attacker has write permission, and that /usr/bin/mount has the SUID bit set (the default configuration on virtually all Linux distributions). The impact is unauthorized read access to root-protected files and block devices, including backup images, disk volumes, and any file containing a valid filesystem. This issue has been patched in version 2.41.4.

## Affected

- `util-linux < 2.41.4`

## Remediation

Upgrade past the affected range:

- `util-linux 2.41.4`

## Vendor advisories

- **RHSA-2026:7180** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-04-09 · [advisory](https://access.redhat.com/errata/RHSA-2026:7180)
- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4, Red Hat Enterprise Linux 10 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27456.json)