CVE-2026-20182: Unauthenticated Cisco SD-WAN Control-Plane Compromise via vHub Authentication Bypass

CVE-2026-20182 is a critical authentication-bypass in Cisco Catalyst SD‑WAN vdaemon (CVSS 10.0) whereby an attacker can establish a DTLS session, send a crafted CHALLENGE_ACK claiming device_type=2 (vHub) to bypass certificate and identity validation, be marked authenticated, and then perform privileged actions including injecting SSH keys into /home/vmanage-admin/.ssh/authorized_keys and gaining NETCONF access; Cisco has released fixed software releases and advises immediate patching as no configuration workaround fully mitigates the issue.