MCP stdio server config command injection via unvalidated test endpoints - ATR-2026-00567 (2a12e6a7-67cc-5e67-8f37-0c4e4f140bf0)
An MCP server config (command/args/env for the stdio transport) supplied in an agent request spawns the given command on the host. Detects a config whose command is a raw shell / carries shell metacharacters, or whose args pass a code-execution flag (-c/-e) with a payload. Generalizes beyond CVE-2026-42271 (LiteLLM) to any endpoint that accepts an MCP stdio config.