CVE-2026-53168 fuse: reject fuse_notify() pagecache ops on directories
A malicious FUSE daemon can trigger a kernel warning and potential denial of service by sending invalid pagecache operations on directories.
- 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-2026-53168?
CVE-2026-53168 is a medium-severity denial of service vulnerability in Linux kernel, published on 25 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:
fuse: reject fuse_notify() pagecache ops on directories
The operations FUSE_NOTIFY_STORE and FUSE_NOTIFY_RETRIEVE allow the FUSE daemon to actively write/read pagecache contents.
For directories with FOPEN_CACHE_DIR, the pagecache is used as kernel-internal cache storage, and userspace is not supposed to have direct access to this cache - in particular, fuse_parse_cache() will hit WARN_ON() if the cache contains bogus data.
Reject FUSE_NOTIFY_STORE and FUSE_NOTIFY_RETRIEVE on anything other than regular files with -EINVAL.
Which versions are affected by CVE-2026-53168?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53168?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-53168 being exploited?
There is no known exploitation of CVE-2026-53168 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-90704, BELL-CVE-2026-53168, DEBIAN-CVE-2026-53168, GHSA-r29v-cgxr-pghg, ROOT-OS-DEBIAN-11-CVE-2026-53168, ROOT-OS-DEBIAN-12-CVE-2026-53168 and 3 more.