CVE-2026-14258 is a vulnerability in dhcpcd's IPv6 Neighbor Discovery Router Advertisement processing. An adjacent attacker can send a specially crafted IPv6 Router Advertisement containing a zero-length Neighbor Discovery option, causing the parser to enter a non-advancing infinite loop. This results in excessive CPU consumption and a denial of service condition. Red Hat has rated this issue as Moderate severity and released patches for affected Red Hat Enterprise Linux 10 versions. Mitigations include disabling IPv6 Router Advertisement processing where not needed or filtering untrusted ICMPv6 Router Advertisements.