The aws-mcp-server service has a command injection flaw that allows an unauthenticated attacker to supply an unvalidated command string which is executed directly by the server. This vulnerability corresponds to CWE‑78 (OS Command Injection) and can lead to arbitrary code execution with the privileges of the MCP server process, potentially compromising the entire environment. The public advisory reports the flaw as critical with a CVSS score of 9.8.

The affected product is AWS MCP Server. The advisory does not list any specific version range, so the flaw may affect all existing installations of the service until a vendor‑issued update is released. Administrators should review their installed versions against vendor documentation.

The risk is high because no authentication is required and the flaw can be triggered from a network‑facing interface. The exact attack vector is not detailed in the advisory, so we infer that it involves a vulnerable endpoint that receives command strings. The EPSS score is not available, and the vulnerability is not in the KEV catalog, but the CVSS score of 9.8 indicates a critical severity. The potential impact includes full compromise of the server and the systems it manages.