CVE-2025-58444highCode execution2025-09-08
CVE-2025-58444: MCP Inspector is Vulnerable to Potential Command Execution via XSS When Connecting to an Untrusted MCP Server
An XSS flaw exists in the MCP Inspector local development tool when it renders a redirect URL returned by a remote MCP server.
What it is
An XSS flaw exists in the MCP Inspector local development tool when it renders a redirect URL returned by a remote MCP server. If the Inspector connects to an untrusted server, a crafted redirect can inject script into the Inspector context and, via the built-in proxy, be leveraged to trigger arbitrary command execution on the developer machine. Version 0.16.6 hardens URL handling/validation and prevents script execution.
How to check
- Affected: @modelcontextprotocol/inspector (npm) < 0.16.6.
- Compare your installed version with the range above (command below).
How to fix
- Upgrade @modelcontextprotocol/inspector to 0.16.6 or later.
npm ls @modelcontextprotocol/inspectorSources
More advisories for this tool
- criticalCVE-2026-32871: FastMCP OpenAPI Provider has an SSRF & Path Traversal Vulnerability
- criticalCVE-2025-6514: mcp-remote exposed to OS command injection via untrusted MCP server connections
- criticalCVE-2025-49596: MCP Inspector proxy server lacks authentication between the Inspector client and proxy
- highCVE-2026-104850: MCP TypeScript SDK: OAuth client could send credentials to an authorization server chosen by the MCP server