alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET WEB_SERVER Cisco Catalyst SD-WAN Manager API Authentication Bypass (CVE-2026-76504)"; flow:established,to_server; http.uri; content:"/"; pcre:"/^(?!j_security_check)(?:j|%(?:25)?6[aA])(?:_|%(?:25)?5[fF])(?:s|%(?:25)?73)(?:e|%(?:25)?65)(?:c|%(?:25)?63)(?:u|%(?:25)?75)(?:r|%(?:25)?72)(?:i|%(?:25)?69)(?:t|%(?:25)?74)(?:y|%(?:25)?79)(?:_|%(?:25)?5[fF])(?:c|%(?:25)?63)(?:h|%(?:25)?68)(?:e|%(?:25)?65)(?:c|%(?:25)?63)(?:k|%(?:25)?6[bB])/R"; http.request_body; content:"j_username|3d|viptela-reserved-"; fast_pattern; pcre:"/^(?:cloudops|uc)(?:\x26|$)/R"; content:"j_password|3d|"; reference:url,www.vulncheck.com/blog/revenge-of-the-sd-wan-cve-2026-76504; reference:cve,2026-76504; classtype:attempted-user; sid:2072391; rev:1; metadata:attack_target Server, tls_state TLSDecrypt, created_at 2026_10_08, cve CVE_2026_76504, deployment Perimeter, deployment Internal, confidence High, signature_severity Major, tag Exploit, updated_at 2026_10_08, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)