CVE-2026-64266 fuse: re-lock request before returning from fuse_ref_folio()
A use-after-free vulnerability in the Linux kernel FUSE subsystem allows attackers to execute arbitrary code or escalate privileges via race conditions.
- 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-2026-64266?
CVE-2026-64266 is a high-severity use after free vulnerability in Linux kernel, published on 25 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 returning from fuse_ref_folio()
fuse_ref_folio() unlocks the request but does not re-lock it before returning. fuse_chan_abort() can end the request and the async end callback (eg fuse_writepage_free()) can free the args while the subsequent copy chain logic after fuse_ref_folio() accesses them, leading to use-after-free issues.
Fix this by locking the request in fuse_ref_folio() before returning.
Which versions are affected by CVE-2026-64266?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-64266?
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-2026-64266 being exploited?
There is no known exploitation of CVE-2026-64266 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-93740, BELL-CVE-2026-64266, DEBIAN-CVE-2026-64266, GHSA-x828-8hm7-w4xw, ROOT-OS-DEBIAN-12-CVE-2026-64266, ROOT-OS-UBUNTU-2204-CVE-2026-64266 and 1 more.