CVE-2026-42271

EIP tracks 1 public exploit for CVE-2026-42271. PoCs published by learner202649.

AI-analyzed exploit summary This repository contains a functional exploit for CVE-2026-42271, targeting LiteLLM's MCP stdio command injection vulnerability. The exploit leverages the POST /mcp-rest/test/connection and POST /mcp-rest/test/tools/list endpoints to execute arbitrary commands on a vulnerable LiteLLM instance.

LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. From version 1.74.2 to before version 1.83.7, two endpoints used to preview an MCP server before saving it — POST /mcp-rest/test/connection and POST /mcp-rest/test/tools/list — accepted a full server configuration in the request body, including the command, args, and env fields used by the stdio transport. When called with a stdio configuration, the endpoints attempted to connect, which spawned the supplied command as a subprocess on the proxy host with the privileges of the proxy process. The endpoints were gated only by a valid proxy API key, with no role check. Any authenticated user — including holders of low-privilege internal-user keys — could therefore run arbitrary commands on the host. This issue has been patched in version 1.83.7.