CVE-2026-27456: util-linux is a random collection of Linux utilities

Q: How do I fix CVE-2026-27456?

util-linux: upgrade to 2.41.4. Exact commands for each OS are on this page.

Q: Is CVE-2026-27456 being exploited?

CVE-2026-27456 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-27456 affect?

CVE-2026-27456 affects util-linux. Severity is medium (CVSS 4.7). 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

Q: How urgent is CVE-2026-27456?

Priority 28/100. Public exploit reference; On your watchlist

Routine

MEDIUM 4.7WATCHLISTUPGRADE

CVE-2026-27456 is a medium-severity flaw (CVSS 4.7) affecting util-linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	4.7 (Medium)
Attack vector	Local
Attack complexity	High
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 96%)
CISA exploited list	No
Weakness	CWE-59, CWE-269, CWE-367
Published	2026-04-03
Last modified	2026-07-24

Publisher (CNA): GitHub, Inc. · Vendor: kernel

Last updated 2026-07-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-03 22:16 UTCPublished CVE record published
2026-07-24 22:10 UTCUpdated Record last modified

kernel util-linux UPGRADE

Affected: < 2.41.4

Fixed in: 2.41.4

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy util-linux || rpm -q util-linux || util-linux --version

2. UPGRADE to 2.41.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade util-linux

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade util-linux

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Advisories and coverage

Official advisories

Fedora Security: [SECURITY] Fedora 43 Update: util-linux-2.41.6-1.fc43 2026-10-28
Fedora Security: [SECURITY] Fedora 44 Update: util-linux-2.41.6-1.fc44 2026-10-28

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-27456?

util-linux: upgrade to 2.41.4. Exact commands for each OS are on this page.

Is CVE-2026-27456 being exploited?

CVE-2026-27456 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-27456 affect?

CVE-2026-27456 affects util-linux. Severity is medium (CVSS 4.7). 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

How urgent is CVE-2026-27456?

Priority 28/100. Public exploit reference; On your watchlist

Related CVEs

CVE-2026-3184 LOW 3.7 MITIGATE MITIGATE A flaw was found in util-linux

References

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