excel-mcp-server is a Model Context Protocol server for Excel file manipulation. A path traversal vulnerability exists in excel-mcp-server versions up to and in…

A path traversal vulnerability in excel-mcp-server versions up to 0.1.7 allows unauthenticated remote attackers to read, write, and overwrite arbitrary files on the host filesystem. The vulnerability occurs when running in SSE or Streamable-HTTP transport mode, where attackers can supply crafted filepath arguments to any of the 25 exposed MCP tool handlers. The server's get_excel_path() function fails to properly enforce directory boundaries by passing absolute paths without validation and joining relative paths without resolution. Combined with zero authentication and default binding to all interfaces (0.0.0.0), this enables trivial remote exploitation. The vulnerability is fixed in version 0.1.8.