Vulnerability · Published Jun 13, 2025 · Assigned by GitHub_M
CVE-2025-49596MCP Inspector proxy server lacks authentication between the Inspector client and proxy
Critical 9.4
In plain English
A critical-severity missing authentication in inspector from modelcontextprotocol. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 44.5% (higher than 99% of all known vulnerabilities). Ready-made attack tooling exists: Nuclei, public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official description
The MCP inspector is a developer tool for testing and debugging MCP servers. Versions of MCP Inspector below 0.14.1 are vulnerable to remote code execution due to lack of authentication between the Inspector client and proxy, allowing unauthenticated requests to launch MCP commands over stdio. Users should immediately upgrade to version 0.14.1 or later to address these vulnerabilities.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @modelcontextprotocol/inspector | 0.14.1 | GHSA-7f8r-222p-6f5g |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| modelcontextprotocol | inspector | < 0.14.1 |
Weakness: CWE-306 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
References
- https://github.com/modelcontextprotocol/inspector/security/advisories/GHSA-7f8r-222p-6f5g x_refsource_CONFIRM
- https://github.com/modelcontextprotocol/inspector/commit/50df0e1ec488f3983740b4d28d2a968f12eb8979 x_refsource_MISC
- https://thenewstack.io/mcp-vulnerability-exposes-the-ai-untrusted-code-crisis x_refsource_MISC
- https://www.oligo.security/blog/critical-rce-vulnerability-in-anthropic-mcp-inspector-cve-2025-49596 x_refsource_MISC