LiteLLM MCP Unauthenticated Server Registration RCE (CVE-2026-30623) - ATR-2026-00416 (22064386-fbcd-5e84-8eca-c092a878fcd6)
Detects exploitation of CVE-2026-30623 in LiteLLM (fixed in v1.83.7-stable). The MCP server-registration interface is reachable without authentication, allowing an unauthenticated remote attacker to POST a malicious STDIO server configuration. When any agent session subsequently initialises, the registered command (e.g. bash -c <payload>) is executed on the LiteLLM host. Part of the OX Security MCP-by-design disclosure (2026-04-15) which covers a class of unauthenticated MCP-config-to-RCE flaws across LiteLLM, LangChain, LangFlow. Distinct from CVE-2026-40933 (Flowise authenticated bypass) — this rule targets the unauthenticated-registration variant.