ALPINE-CVE-2026-27456
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.
ALPINE-CVE-2026-27456
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:ALPINE-CVE-2026-27456
util-linux
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 2.41.6-r0
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
util-linux
Source reference: /affected/1/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 2.41.4-r0
Source reference:
/affected/1/ranges - Prerequisites
- Not stated in this record
util-linux
Source reference: /affected/2/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 2.41.4-r0
Source reference:
/affected/2/ranges2.42.3-r0Source reference:
/affected/2/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.41.6-r0"
}
]
}
],
"package": {
"name": "util-linux",
"purl": "pkg:apk/alpine/util-linux?arch=source",
"ecosystem": "Alpine:v3.22"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-27456.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.41.4-r0"
}
]
}
],
"package": {
"name": "util-linux",
"purl": "pkg:apk/alpine/util-linux?arch=source",
"ecosystem": "Alpine:v3.23"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-27456.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.41.4-r0"
},
{
"fixed": "2.42.3-r0"
}
]
}
],
"package": {
"name": "util-linux",
"purl": "pkg:apk/alpine/util-linux?arch=source",
"ecosystem": "Alpine:v3.24"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-27456.json"
},
"ecosystem_specific": {}
}
]Publisher severity
No explicit severity was provided.
- Event
- #54207 · Revision 1
- Added to Heist Feed
- Publisher date