CVE-2026-53261 devlink: Release nested relation on devlink free
A memory leak in the Linux kernel devlink subsystem can lead to resource exhaustion and 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-2026-53261?
CVE-2026-53261 is a medium-severity memory corruption 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:
devlink: Release nested relation on devlink free
devlink relation state is normally released from devl_unregister(), which calls devlink_rel_put(). This misses devlink instances that get a nested relation before registration and then fail probe before devl_register() is reached.
That flow can happen for SFs. The child devlink gets linked to its parent before registration, then a later probe error calls devlink_free() directly. Since the instance was never registered, devl_unregister() is not called and devlink->rel is leaked.
Release any pending relation from devlink_free() as well. The registered path is unchanged because devl_unregister() already clears devlink->rel before devlink_free() runs.
Weakness: CWE-401
Which versions are affected by CVE-2026-53261?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53261?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-53261 being exploited?
There is no known exploitation of CVE-2026-53261 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-53261, DEBIAN-CVE-2026-53261, GHSA-q96w-jfjr-xww5, ROOT-OS-UBUNTU-2404-CVE-2026-53261, UBUNTU-CVE-2026-53261.