CVE-2026-78410
Published: September 5, 2026Last modified: October 6, 2026
Description
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.8 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | util-linux | Fixed (2.38.1-r9) |
| 25 LTS | util-linux | Fixed (2.41.6-r1) | |
| Stream | util-linux | Fixed (2.42.3-r1) | |
| Hardened Containers | 23 LTS | util-linux | Fixed (2.38.1-r9) |
| 25 LTS | util-linux | Fixed (2.41.6-r1) | |
| Stream | util-linux | Fixed (2.42.3-r1) |
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/commit/b21f4cee55f723b045920dad5ce48a659d34cac8