CVE-2026-98379

A flaw was found in the Linux kernel's netfilter subsystem. An unprivileged local user can cause a Denial of Service (DoS) by triggering a system crash through a null pointer dereference (an attempt to access invalid memory). This issue occurs during IPv6 reverse-path filtering when the kernel evaluates routes that lack associated interface device data following network configuration changes. By generating traffic that prompts lookups on these incomplete routes, a local attacker can force a kernel panic.

This vulnerability is rated as Moderate severity because exploitation requires local access and complex prerequisites to manipulate routing states, limiting the potential impact to a system crash (denial of service). To trigger the condition, an unprivileged user must leverage unprivileged user and network namespaces to configure an external nexthop device below the minimum IPv6 MTU, leaving invalid route objects in the routing table. Deployments where unprivileged user namespaces are disabled or where IPv6 reverse-path filtering is not utilized are not susceptible to this attack from unprivileged accounts.

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.