alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (
msg:"ET WEB_SPECIFIC_APPS Next.js WebSocket Upgrade Handler Server-Side Request Forgery (CVE-2026-44578)";
flow:established,to_server;
http.uri;
content:"http"; startswith;
pcre:"/^s?(?:\x3a|\x25(?:25)?3[aA])(?:\x2f|\x25(?:25)2[fF]){2}/R";
http.header;
content:"upgrade|3a 20|websocket"; fast_pattern; nocase;
content:"sec-websocket-version|3a 20|13"; nocase;
content:"sec-websocket-key|3a 20|"; nocase;
reference:url,app.hacktron.ai/disclosed/scans/web_dmVyY2VsL25leHQtanMtbWlycm9y_1774994038380_2hfQkCKG/findings/66f26e9e-a71f-4997-85be-a0b5fa3b7d89;
reference:cve,2026-44578;
classtype:web-application-attack;
sid:2069469; rev:1;
metadata:attack_target Server, tls_state TLSDecrypt, created_at 2026_05_28, cve CVE_2026_44578, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence High, signature_severity Major, tag Exploit, updated_at 2026_05_28, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;
target:dest_ip;
)