alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET WEB_SPECIFIC_APPS SEPPmail Gateway RCE via Arbitrary File Write (CVE-2026-2743)"; flow:established,to_server; http.uri; content:"/v1/file.app"; fast_pattern; http.request_body; content:"|22|files|22 3a|"; content:"|22|file|22 3a|"; distance:0; pcre:"/^\s*\x22[^\x22]*?(?:(?:\x2e|%+(?:25)?2[Ee]|%+(?:25)?32%+(?:25)?[46]5){1,2}(?:\x2f|\x5c|%+(?:25)?(?:25)?5[Cc]|%+(?:25)?2[Ff]){1,}){2,}/R"; http.method; content:"POST"; reference:url,labs.infoguard.ch/posts/seppmail_secure_e-mail_gateway_rce_vulnerabilities_cve-2026-2743_cve-2026-7864_cve-2026-44127_cve-2026-44128/; reference:cve,2026-2743; classtype:web-application-attack; sid:2069393; rev:1; metadata:attack_target Server, tls_state TLSDecrypt, created_at 2026_05_22, cve CVE_2026_2743, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence High, signature_severity Major, tag Exploit, updated_at 2026_05_22, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)