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. 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.
Published Sep 8, 2025 · Updated Sep 26, 2025
Affected packages
@modelcontextprotocol/inspector
- Ecosystem
- npm
- Affected
- < 0.16.6
- Fixed in
- 0.16.6
- Check
npm ls @modelcontextprotocol/inspector
Advisory details
From the GitHub Advisory Database (CC BY 4.0).
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.
Thank you to the following researchers for their reports and contributions: > * Raymond (Veria Labs) > * Gavin Zhong, & Shuyang Wang, .
Credited to cai0duque.
References
- https://github.com/modelcontextprotocol/inspector/security/advisories/GHSA-g9hg-qhmf-q45m
- https://github.com/modelcontextprotocol/inspector/commit/650f3090d26344a672026b737d81586595bb1f60
- https://nvd.nist.gov/vuln/detail/CVE-2025-58444
- https://www.npmjs.com/package/@modelcontextprotocol/inspector/v/0.16.6
- https://github.com/advisories/GHSA-g9hg-qhmf-q45m
How this page is made: the data panel comes from the GitHub Advisory Database, CISA’s KEV catalog, the NVD and FIRST EPSS, and updates twice a day. No analysis has been written for this entry yet. Methodology