Advisoriesby IbisRed HatCVE-2026-78409
Red Hat Enterprise Linux 10: link following
No fix yet
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 versions
| Package | Affected | Fixed in |
|---|---|---|
| Red Hat Enterprise Linux 10 Product | all versions | No fix yet |
| Red Hat Enterprise Linux 7 Product | all versions | No fix yet |
| Red Hat Enterprise Linux 8 Product | all versions | No fix yet |
| Red Hat Enterprise Linux 9 Product | all versions | No fix yet |
| all versions | No fix yet | |
| all versions | No fix yet | |
| Red Hat OpenShift Container Platform 4 Product | all versions | No fix yet |
| all versions | No fix yet | |
| Red Hat OpenShift Container Platform 5 Product | all versions | No fix yet |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-59