CVE-2026-90318 fat: release buffer head after rebuilding parent
A missing buffer head release in the Linux kernel FAT filesystem can lead to memory corruption and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90318?
CVE-2026-90318 is a memory corruption vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
fat: release buffer head after rebuilding parent
fat_scan_logstart() leaves the matching directory entry's buffer head in sinfo.bh for the caller to release, just like fat_scan().
fat_rebuild_parent() uses the directory entry to rebuild the parent inode for the nostale_ro NFS export path, but does not release sinfo.bh after a successful scan. Release it once fat_build_inode() has consumed the directory entry data.
Which versions are affected by CVE-2026-90318?
How do I fix CVE-2026-90318?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-90318 being exploited?
There is no known exploitation of CVE-2026-90318 in the wild and no public exploit code.
Sources
Also known as AZL-102612, BELL-CVE-2026-90318, DEBIAN-CVE-2026-90318, GHSA-qqhm-c5f5-75r9, UBUNTU-CVE-2026-90318.