CVE-2025-21763

In the Linux kernel, the following vulnerability has been resolved:

neighbour: use RCU protection in __neigh_notify()

__neigh_notify() can be called without RTNL or RCU protection.

Use RCU protection to avoid potential UAF.

This vulnerability is rated as Moderate because exploitation requires local system access to trigger neighbor notification events that expose the race condition. Although the synchronization flaw in the kernel's neighbor management subsystem could lead to memory corruption or an unexpected kernel crash, it cannot be initiated directly across network boundaries without local execution. Consequently, the practical risk in default Red Hat Enterprise Linux environments is constrained to a local denial of service.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.