alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-55605 DeepSeek MCP Server - Unauthenticated /mcp Initialize"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/mcp"; http.request_body; content:"initialize"; fast_pattern; content:"protocolVersion"; classtype:web-application-attack; reference:cve,CVE-2026-55605; reference:url,https://www.exploit.observer/?keyword=CVE-2026-55605&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=deepseek&match=exact; sid:1081807; rev:1;)