Description (CNA)
The X-mount.subdir option uses a detached-tree fast path on Linux 6.15 and later and passes the configured subdirectory to open_tree() with AT_SYMLINK_NOFOLLOW. That flag does not stop intermediate symlink traversal or keep resolution inside the newly mounted filesystem. A local unprivileged user with an fstab-authorized X-mount.subdir entry can attach a host path at the intended mountpoint.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Red Hat / Red Hat Hardened Images | unaffected 2.42.2-3.4.hum1 before * |
| Red Hat / Red Hat Enterprise Linux 10 | unaffected |
| Red Hat / Red Hat Enterprise Linux 7 | unaffected |
| Red Hat / Red Hat Enterprise Linux 8 | unaffected |
| Red Hat / Red Hat Enterprise Linux 9 | unaffected |
| Red Hat / Red Hat Enterprise Linux 9 | unaffected |
| Red Hat / Red Hat Enterprise Linux 9 | unaffected |
| Red Hat / Red Hat OpenShift Container Platform 4 | unaffected |
| Red Hat / Red Hat OpenShift Container Platform 4 | unaffected |
CWE
CWE-59
References
- https://access.redhat.com/errata/RHSA-2026:63162
- https://access.redhat.com/security/cve/CVE-2026-78409
- https://bugzilla.redhat.com/show_bug.cgi?id=2522607
- https://github.com/util-linux/util-linux/security/advisories/GHSA-8f2p-47x3-43mv
ADP enrichment
No English description supplied.