CVE-2026-53129 fs/mbcache: cancel shrink work before destroying the cache
A use-after-free in the Linux kernel mbcache allows privileged users to trigger memory corruption, potentially leading to code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53129?
CVE-2026-53129 is a high-severity use after free vulnerability in Linux kernel, published on 24 Jun 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:
fs/mbcache: cancel shrink work before destroying the cache
mb_cache_destroy() calls shrinker_free() and then frees all cache entries and the cache itself, but it does not cancel the pending c_shrink_work work item first.
If mb_cache_entry_create() schedules c_shrink_work via schedule_work() and the work item is still pending or running when mb_cache_destroy() runs, mb_cache_shrink_worker() will access the cache after its memory has been freed, causing a use-after-free.
This is only reachable by a privileged user (root or CAP_SYS_ADMIN) who can trigger the last put of a mounted ext2/ext4/ocfs2 filesystem.
Cancel the work item with cancel_work_sync() before calling shrinker_free(), ensuring the worker has finished and will not be rescheduled before the cache is torn down.
Weakness: CWE-416
Which versions are affected by CVE-2026-53129?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53129?
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-2026-53129 being exploited?
There is no known exploitation of CVE-2026-53129 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-90546, BELL-CVE-2026-53129, DEBIAN-CVE-2026-53129, GHSA-76p3-3v32-9xxh, ROOT-OS-DEBIAN-11-CVE-2026-53129, ROOT-OS-DEBIAN-12-CVE-2026-53129 and 1 more.