alert http any any -> $HOME_NET any (msg:"ET WEB_SPECIFIC_APPS Rails Active Storage BMP Direct Upload (CVE-2026-66066)"; flow:established,to_server; http.uri; content:"/rails/active_storage/direct_uploads"; fast_pattern; http.request_body; strip_whitespace; content:"|22|filename|22 3a 22|profile.bmp|22|"; content:"|22|content_type|22 3a 22|image/bmp|22|"; http.method; content:"POST"; reference:url,github.com/rails/rails/security/advisories/GHSA-xr9x-r78c-5hrm; reference:cve,2026-66066; reference:url,gist.github.com/win3zz/ae02cb1c3be0b79f69b609f559e1f179; classtype:web-application-attack; sid:2072273; rev:1; metadata:attack_target Server, tls_state TLSDecrypt, created_at 2026_09_28, cve CVE_2026_66066, deployment Perimeter, deployment Internal, confidence High, signature_severity Major, tag Exploit, updated_at 2026_09_28, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)