CVE-2026-53388 fuse: re-lock request before replacing page cache folio
A use-after-free vulnerability in the Linux kernel's FUSE filesystem allows attackers to potentially execute code or escalate privileges.
- 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-2026-53388?
CVE-2026-53388 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:
fuse: re-lock request before replacing page cache folio
fuse_try_move_folio() unlocks the request on entry but does not re-lock it on the success path. This means fuse_chan_abort() can end the request and free the fuse_io_args (eg fuse_readpages_end()) while the subsequent copy chain logic after fuse_try_move_folio() accesses the fuse_io_args, leading to use-after-free issues.
Fix this by calling lock_request() before replace_page_cache_folio(). This ensures the request is locked on the success path which will prevent the fuse_io_args from being freed while the later copying logic runs, and also ensures that the ap->folios[i]->mapping is never null since ap->folios[i] will always point to the newfolio after replace_page_cache_folio().
Weakness: CWE-416
Which versions are affected by CVE-2026-53388?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53388?
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-2026-53388 being exploited?
There is no known exploitation of CVE-2026-53388 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-53388, DEBIAN-CVE-2026-53388, GHSA-45w6-5frg-3vfq, ROOT-OS-DEBIAN-11-CVE-2026-53388, ROOT-OS-UBUNTU-2204-CVE-2026-53388, UBUNTU-CVE-2026-53388.