CVE-2026-43454

A flaw was found in the Linux kernel's netfilter nf_tables component. This vulnerability allows for duplicate device registration when handling network device registration notifications. Such duplicate registrations can lead to unexpected system behavior or instability.

A flaw of moderate impact was found in the Linux kernel's netfilter nf_tables component as shipped in Red Hat Enterprise Linux 10 and Red Hat In-Vehicle OS 2.0. When handling a NETDEV_REGISTER notification, netdev hook handling can register the same network device twice, because the device may already have been added by nft_netdev_hook_alloc() when the hook was created. This duplicate registration breaks hook lifecycle accounting and can lead to unexpected system behavior or instability, including a potential denial of service during later unregister or cleanup paths. Exploitation requires local access with the privileges needed to configure nftables netdev hooks (such as CAP_NET_ADMIN, which may be delegated to less trusted users within containers or network namespaces). Earlier Red Hat Enterprise Linux streams (RHEL 6, 7, 8, and 9, as well as RHEL 10.0 and 10.1) are not affected because the code that introduced this behavior is not present in those versions. For the affected streams (RHEL 10.2, RHEL 10.3, and Red Hat In-Vehicle OS 2.0 including core), the flaw is delegated to the kernel maintenance team and a fix is being pursued through the standard update process. Red Hat rates the severity of this flaw as MODERATE, lower than the upstream CVE.org rating of IMPORTANT (CVSS 3.1 score 7.8), because exploitation requires local privileged access and the primary consequence is limited to system availability.

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 do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.