alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET WEB_SPECIFIC_APPS Citrix NetScaler Unauthenticated Remote Code Execution (CVE-2026-8452)"; flow:established,to_server; http.uri; content:"/cgi/samlauth"; fast_pattern; http.method; content:"POST"; http.request_body; content:"SAMLResponse|3d|"; base64_decode:relative; base64_data; content:"|3c|ds:SignedInfo|3e|"; content:"PrefixList|3d 22|"; distance:0; pcre:"/^[^\x22]{2500,}\x22/R"; reference:url,labs.watchtowr.com/youre-back-in-the-room-citrix-netscaler-pre-auth-rce-cve-2026-8452/; reference:cve,2026-8452; classtype:web-application-attack; sid:2071537; rev:1; metadata:affected_product Citrix, attack_target Server, tls_state TLSDecrypt, created_at 2026_08_14, cve CVE_2026_8452, deployment Perimeter, deployment Internal, confidence High, signature_severity Major, tag Exploit, updated_at 2026_08_14, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)