alert smtp any any -> [$HOME_NET,$SMTP_SERVERS] any (msg:"ET EXPLOIT Microsoft Exchange Outlook Web Access (OWA) Cross-Site Scripting (CVE-2026-42897)"; flow:established,to_server; content:"Microsoft SMTP Server"; fast_pattern; content:"|3c|img "; content:"data|3a|image|2f|svg"; distance:0; content:"xml|3b|base64"; within:20; pcre:"/^[^\x22]*?on[a-z]+=[^\x22]*?[\x28\x5b\x7b]/R"; reference:cve,2026-42897; classtype:web-application-attack; sid:2071330; rev:1; metadata:affected_product Microsoft_Exchange, attack_target Server, created_at 2026_07_28, cve CVE_2026_42897, deployment Perimeter, deployment Internal, confidence High, signature_severity Major, tag Exploit, updated_at 2026_07_28, former_sid 2868078, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)