CVE-2025-68817 ksmbd: fix use-after-free in ksmbd_tree_connect_put under concurrency
A use-after-free vulnerability in the Linux kernel's ksmbd module allows attackers to potentially execute code or escalate privileges under high concurrency.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-68817?
CVE-2025-68817 is a critical use after free vulnerability in Linux kernel, published on 13 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free in ksmbd_tree_connect_put under concurrency
Under high concurrency, A tree-connection object (tcon) is freed on a disconnect path while another path still holds a reference and later executes *_put()/write on it.
Weakness: CWE-416
Which versions are affected by CVE-2025-68817?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-68817?
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-2025-68817 being exploited?
There is no known exploitation of CVE-2025-68817 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-68817, DEBIAN-CVE-2025-68817, GHSA-77h3-779x-v4x3, ROOT-OS-DEBIAN-12-CVE-2025-68817, ROOT-OS-DEBIAN-13-CVE-2025-68817, ROOT-OS-UBUNTU-2204-CVE-2025-68817 and 2 more.