DEBIAN-CVE-2026-27456

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Source
https://security-tracker.debian.org/tracker/CVE-2026-27456
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27456.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-27456
Upstream
Published
2026-04-03T22:16:25Z
Modified
2026-09-14T17:03:01Z
Severity
  • 4.7 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N CVSS Calculator
Summary
[none]
Details

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.

References

Affected packages

Debian:12 / util-linux

Package

Name
util-linux
Purl
pkg:deb/debian/util-linux?arch=source&distro=bookworm

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.38.1-5
2.38.1-5+deb12u1
2.38.1-5+deb12u2
2.38.1-5+deb12u3
2.38.1-5+loong64
2.38.1-6
2.39.1-1
2.39.1-2
2.39.1-3
2.39.1-4
2.39.2-1
2.39.2-2
2.39.2-2.1
2.39.2-2.2
2.39.2-3
2.39.2-4
2.39.2-5
2.39.2-6
2.39.3-1
2.39.3-2
2.39.3-3
2.39.3-4
2.39.3-5
2.39.3-6
2.39.3-6.1~exp1
2.39.3-6.1
2.39.3-7
2.39.3-8
2.39.3-9
2.39.3-10
2.39.3-11
2.40~rc2-1
2.40~rc2-2
2.40~rc2-3
2.40~rc2-4
2.40~rc2-5
2.40~rc2-6
2.40~rc2-7
2.40~rc2-8
2.40-1
2.40-2
2.40-3
2.40-4
2.40-5
2.40-6
2.40-7
2.40-8
2.40.1-1
2.40.1-2
2.40.1-3
2.40.1-4
2.40.1-4+hurd.1
2.40.1-6
2.40.1-7
2.40.1-8
2.40.1-8.1
2.40.1-9
2.40.2-1
2.40.2-2
2.40.2-3
2.40.2-4
2.40.2-5
2.40.2-6
2.40.2-7
2.40.2-8
2.40.2-9
2.40.2-10
2.40.2-11
2.40.2-12
2.40.2-12+hurd.1
2.40.2-13
2.40.2-14
2.40.3-1
2.40.4-1
2.40.4-2
2.40.4-3
2.40.4-4
2.40.4-5
2.41~rc1-1
2.41~rc1-2
2.41~rc2-1
2.41-1
2.41-2
2.41-3
2.41-4
2.41-5
2.41.1-1
2.41.1-2
2.41.1-3
2.41.1-4
2.41.2-1
2.41.2-2
2.41.2-3
2.41.2-4
2.41.3-1
2.41.3-2
2.41.3-3
2.41.3-4
2.42~rc1-1
2.42~rc1-2
2.42~rc1-3
2.42~rc2-1
2.42-1
2.42-2
2.42-3
2.42-4
2.42-5
2.42-6
2.42.1-1
2.42.1-2
2.42.1-3
2.42.1-4
2.42.1-5
2.42.1-6
2.42.2-1
2.42.2-2
2.42.2-3
2.42.2-4
2.42.3-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27456.json"

Debian:13 / util-linux

Package

Name
util-linux
Purl
pkg:deb/debian/util-linux?arch=source&distro=trixie

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.41.5-0+deb13u1

Affected versions

2.*
2.41-5
2.41.1-1
2.41.1-2
2.41.1-3
2.41.1-4
2.41.2-1
2.41.2-2
2.41.2-3
2.41.2-4
2.41.3-1
2.41.3-2
2.41.3-3
2.41.3-4

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27456.json"

Debian:14 / util-linux

Package

Name
util-linux
Purl
pkg:deb/debian/util-linux?arch=source&distro=forky

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.42-1

Affected versions

2.*
2.41-5
2.41.1-1
2.41.1-2
2.41.1-3
2.41.1-4
2.41.2-1
2.41.2-2
2.41.2-3
2.41.2-4
2.41.3-1
2.41.3-2
2.41.3-3
2.41.3-4
2.42~rc1-1
2.42~rc1-2
2.42~rc1-3
2.42~rc2-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27456.json"