CVE-2025-21660 ksmbd: fix unexpectedly changed path in ksmbd_vfs_kern_path_locked
An attacker can exploit a path handling error in the ksmbd kernel module to modify files or execute code via unexpected path changes.
- 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-2025-21660?
CVE-2025-21660 is a medium-severity path traversal vulnerability in Linux kernel, published on 21 Jan 2025. 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:
ksmbd: fix unexpectedly changed path in ksmbd_vfs_kern_path_locked
When `ksmbd_vfs_kern_path_locked` met an error and it is not the last entry, it will exit without restoring changed path buffer. But later this buffer may be used as the filename for creation.
Which versions are affected by CVE-2025-21660?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-21660?
Apply the vendor's patch.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2025-21660 being exploited?
There is no known exploitation of CVE-2025-21660 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-21660, DEBIAN-CVE-2025-21660, GHSA-jj94-6v6v-cc35, UBUNTU-CVE-2025-21660.