CVE-2025-39980

A flaw was found in the Linux kernel’s nexthop subsystem: the code did not forbid changing the FDB (Forwarding Database) status of a nexthop while it is part of a nexthop group. This can result in creation of invalid or inconsistent routing configurations — for example, grouping non-FDB nexthops with FDB-flagged nexthops, or vice versa. Under certain conditions this may lead to routing misconfiguration or forwarding failures.

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.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.