Vulnerability Description
util-linux versions through 2.41.5 and 2.42.2 fail to check mount helper exit status before running post-mount hooks, allowing unprivileged users to execute privileged operations on pre-existing filesystems. Attackers can exploit X-mount.idmap or X-mount.owner hooks to clone filesystems with inherited suid bits or modify target inode permissions after a helper fails, achieving privilege escalation.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/util-linux/util-linux
- https://github.com/util-linux/util-linux/blob/v2.42.2/libmount/src/context_mount
- https://github.com/util-linux/util-linux/blob/v2.42.2/libmount/src/context_mount
- https://github.com/util-linux/util-linux/commit/1d14676ea70003e9f5b2a6a76af0cadb
- https://github.com/util-linux/util-linux/commit/a15c00a9e545aa8b9cf6ec0f888ff6c7
- https://github.com/util-linux/util-linux/commit/f57cea130839c0af8dc0525274267ae4
- https://github.com/util-linux/util-linux/security/advisories/GHSA-m25x-3hj9-m26f
- https://www.vulncheck.com/advisories/util-linux-libmount-privilege-escalation-vi
- https://github.com/util-linux/util-linux/security/advisories/GHSA-m25x-3hj9-m26f
FAQ
What is CVE-2026-76642?
CVE-2026-76642 is a vulnerability with a CVSS score of 7.8 (HIGH). util-linux versions through 2.41.5 and 2.42.2 fail to check mount helper exit status before running post-mount hooks, allowing unprivileged users to execute privileged operations on pre-existing files...
How severe is CVE-2026-76642?
CVE-2026-76642 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-76642?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.