CVE-2026-20118
Publiée le 2026-03-11 · Dernière modification le 2026-06-17
Les routeurs Cisco des séries NCS 5500 et 5700 exécutant IOS XR sont vulnérables à une attaque par déni de service qui provoque le plantage de l'unité de traitement réseau (NPU). Un attaquant distant non authentifié peut déclencher cet incident en envoyant un flux continu de paquets spécialement conçus lors de périodes de trafic intense. Bien que l'attaque nécessite un timing et des conditions réseau spécifiques pour réussir, elle peut entraîner une perte de paquets persistante et un arrêt complet du trafic sur l'interface concernée.
DÉTAIL DU VECTEUR CVSS
RÉFÉRENCES
Description officielle du NVD (en anglais)
A vulnerability in the handling of an Egress Packet Network Interface (EPNI) Aligner interrupt in Cisco IOS XR Software for Cisco Network Convergence System (NCS) 5500 Series with NC57 line cards and Cisco NCS 5700 Routers and Cisco IOS XR Software for Third Party Software could allow an unauthenticated, remote attacker to cause the network processing unit (NPU) and ASIC to stop processing, preventing traffic from traversing the interface. This vulnerability is due to the corruption of packets in specific cases when an EPNI Aligner interrupt is triggered while an affected device is experiencing heavy transit traffic. An attacker could exploit this vulnerability by sending a continuous flow of crafted packets to an interface of the affected device. A successful exploit could allow the attacker to cause persistent, heavy packet loss, resulting in a denial of service (DoS) condition. Note: If active exploitation of this vulnerability is suspected, contact the Cisco Technical Assistance Center (TAC) or your contracted maintenance provider. Cisco has assigned this security advisory a Security Impact Rating (SIR) of High rather than Medium as the score indicates. This change was made because the affected device operates within a critical network segment where compromise could lead to significant disruption or exposure, thereby elevating the overall risk beyond the base technical severity.