cvedb.io
CVE-2026-27456
MEDIUM · CVSS 4.7
EPSS exploitation probability: 0%
Published 2026-04-03T22:16:25.400 · Last modified 2026-06-17T10:27:11.017

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 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

Affected products

kernel — util-linux

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.