CVE-2025-68300 fs/namespace: fix reference leak in grab_requested_mnt_ns
A reference leak in the Linux kernel namespace handling allows local attackers to exhaust resources, potentially causing a denial of service.
- 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-2025-68300?
CVE-2025-68300 is a denial of service vulnerability in Linux, published on 16 Dec 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:
fs/namespace: fix reference leak in grab_requested_mnt_ns
lookup_mnt_ns() already takes a reference on mnt_ns. grab_requested_mnt_ns() doesn't need to take an extra reference.
Which versions are affected by CVE-2025-68300?
How do I fix CVE-2025-68300?
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-2025-68300 being exploited?
There is no known exploitation of CVE-2025-68300 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-68300, DEBIAN-CVE-2025-68300, GHSA-w2qx-7hv3-25hh, UBUNTU-CVE-2025-68300.