CVE-2026-10686

Zephyr IPv6 forwarding path has a bug where hop-limit is not decremented in both ipv6_route_packet() branches (explicit-route net_route_packet() and on-link net_route_packet_if()). This causes routed unicast packets to be forwarded indefinitely, enabling a potential on-path attacker to induce a p...

CVE-2026-10686 Missing hop-limit decrement on IPv6 forwarding path allows unbounded packet looping (DoS) in Zephyr routers

Zephyr's IPv6 forwarding path re-sent routed unicast packets without ever decrementing the IPv6 hop limit. Both routing branches of ipv6routepacket subsys/net/ip were affected: the explicit-route path netroutepacket and the on-link cross-interface path netroutepacketif. Each set the packet...