CVE-2026-53381 virtiofs: fix UAF on submount umount
A use-after-free vulnerability in the Linux kernel's virtiofs submount umount process can cause a system crash or potentially allow code execution.
- 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-2026-53381?
CVE-2026-53381 is a high-severity use after free vulnerability in Linux kernel, published on 19 Jul 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:
virtiofs: fix UAF on submount umount
iput() called from fuse_release_end() can Oops if the super block has already been destroyed. Normally this is prevented by waiting for num_waiting to go down to zero before commencing with super block shutdown.
This only works, however, for the last submount instance, as the wait counter is per connection, not per superblock.
Revert to using synchronous release requests for the auto_submounts case, which is virtiofs only at this time.
Weakness: CWE-416
Which versions are affected by CVE-2026-53381?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53381?
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-2026-53381 being exploited?
There is no known exploitation of CVE-2026-53381 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-53381, DEBIAN-CVE-2026-53381, GHSA-525m-f6h4-6w58, ROOT-OS-DEBIAN-11-CVE-2026-53381, ROOT-OS-UBUNTU-2204-CVE-2026-53381, UBUNTU-CVE-2026-53381.