CVE-2026-53012

A flaw was found in the Linux kernel's networking subsystem. When an IPv6 nexthop is replaced with an IPv4 nexthop, a flag indicating the presence of IPv4 members in nexthop groups is not correctly updated. This can lead to IPv6 routes referencing groups that only contain IPv4 members. A local attacker could exploit this issue by crafting specific nexthop configurations, causing a NULL pointer dereference and ultimately leading to a system panic, resulting in a Denial of Service (DoS).

This vulnerability is rated as Moderate impact for Red Hat Enterprise Linux because exploitation requires local access and network administration privileges to manipulate routing objects. While a local attacker capable of configuring nexthop entries—such as within an unprivileged user namespace—can trigger a kernel crash resulting in a denial of service, integrity and confidentiality remain intact. Standard enterprise environments where unprivileged users lack network configuration privileges or where user namespaces are restricted face significantly lower exposure.

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.