A flaw was found in util-linux. Restricted bind mounts take the source path from fstab but do not pin that source before the privileged mount. A local unprivileged user who can replace the authorized source or a writable ancestor can redirect SUID mount(8) to bind another host directory. If the fstab entry also sets X-mount.owner, X-mount.group, or X-mount.mode, root then changes ownership or mode on that redirected inode.
Weakness
The product checks the state of a resource before using that resource, but the resource’s state can change between the check and the use in a way that invalidates the results of the check.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Red Hat Hardened Images | RedHat | util-linux-main-2.42.2-3.4.hum1 | * |
| Util-linux | Ubuntu | upstream | * |
Potential Mitigations
Related Attack Patterns
References
- https://access.redhat.com/errata/RHSA-2026:63162
- https://access.redhat.com/security/cve/CVE-2026-78410
- https://bugzilla.redhat.com/show_bug.cgi?id=2522684
- https://github.com/util-linux/util-linux/security/advisories/GHSA-rh77-686x-2f2m
- https://github.com/util-linux/util-linux/security/advisories/GHSA-rh77-686x-2f2m