CVE-2026-63858

A flaw was found in the Linux kernel's netfilter (nf_tables) subsystem. This vulnerability could lead to a denial of service for network filtering operations. The issue occurs because the process of deleting network hooks improperly modifies a protected list, which can disrupt how network configuration information is read. This could be exploited by an attacker to cause instability or unresponsiveness in the system's network filtering capabilities.

This vulnerability is evaluated as Moderate severity because exploitation requires local system access and elevated network configuration privileges, restricting the impact to a local denial of service without permitting remote exploitation. In Red Hat Enterprise Linux environments, netfilter transaction processing is exposed when managing firewall configurations or when unprivileged user namespaces are enabled. A local user with network administration capabilities in a namespace can induce synchronization issues during interface teardown, causing kernel instability or filtering failure. Earlier platform releases such as RHEL 8 are not affected because the vulnerable hook transaction code is absent.

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.