CVE-2026-98443 xfs: fix cursor and pointer handling when recovering iunlink buckets
A use-after-free vulnerability in the Linux kernel XFS filesystem allows local attackers to potentially execute arbitrary code or escalate privileges.
- 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-2026-98443?
CVE-2026-98443 is a high-severity use after free vulnerability in Linux, published on 18 Oct 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:
xfs: fix cursor and pointer handling when recovering iunlink buckets
LOLLM pointed out a bug in xlog_recover_iunlink_bucket:
1. We don't null out prev_ip after releasing it, which can lead to UAF problems if the inodegc flush call in the loop fails.
at which point I noticed even more bugs:
2. If the inodegc flush inside the loop fails, we also leak @ip.
3. We set prev_agino to agino having already advanced agino, which results in inodes with i_prev_unlinked set to itself.
4. If we exit the bottom of the loop with prev_ip set, then prev_ip aliases ip and we also set its i_prev_unlinked to itself.
Bugs 3 and 4 introduce loops into the unlinked list, though these loops don't surface because we immediately flush each unlinked inode after loading it.
Fix all of these issues.
Which versions are affected by CVE-2026-98443?
How do I fix CVE-2026-98443?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-98443 being exploited?
There is no known exploitation of CVE-2026-98443 in the wild and no public exploit code.
Sources
Also known as AZL-108929, BELL-CVE-2026-98443, DEBIAN-CVE-2026-98443, GHSA-27hr-pwp4-53ph, UBUNTU-CVE-2026-98443.