alert smtp $EXTERNAL_NET any -> $HOME_NET any (msg:"VEDAS CVE-2026-73524 Cypht - Stored Cross-Site Scripting via crafted From header"; flow:established,to_server; content:"From:"; nocase; fast_pattern; pcre:"/^From:[^\r\n]*<\s*\/?(script|img|svg|iframe|body|object|embed|details|video|audio|a\s)/im"; classtype:web-application-attack; reference:cve,CVE-2026-73524; reference:url,https://www.exploit.observer/?keyword=CVE-2026-73524&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=cypht&match=exact; metadata:signature_type network_only; sid:1079208; rev:1;)