alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET WEB_SPECIFIC_APPS Gitea API Authentication Bypass (CVE-2026-20896)"; flow:established,to_server; http.uri; content:"/api/v1/user"; fast_pattern; http.header; content:"authorization|3a 20|token|20|"; nocase; pcre:"/^[^\x0d\x0a]*?(?:(?:\x2e|%+(?:25)?2[Ee]|%+(?:25)?32%+(?:25)?[46]5|%+[cC]0%+[aA][eE]){1,2}(?:\x2f|\x5c|%+(?:25)?(?:25)?5[Cc]|%+(?:25)?2[Ff]|%+[cC]0%+[aA][fF]){1,}){2,}/R"; reference:url,github.com/kaleth4/CVE-2026-20896; reference:cve,2026-20896; classtype:web-application-attack; sid:2071138; rev:1; metadata:affected_product Gitea, attack_target Server, tls_state TLSDecrypt, created_at 2026_07_09, cve CVE_2026_20896, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence High, signature_severity Major, tag Exploit, updated_at 2026_07_09, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)