CVE-2025-49596: @modelcontextprotocol/inspector MCP Inspector Proxy Server Lacks Vulnerability

CRITICAL
Advisory Identifier: GHSA-7f8r-222p-6f5g
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CWE-306
Published
Advisory Summary

CVE-2025-49596 is a CRITICAL mcp inspector proxy server lacks vulnerability (CWE-306: Missing Authentication for Critical Function) affecting @modelcontextprotocol/inspector libraries in the npm ecosystem. The issue involves mcp inspector proxy server lacks authentication between the inspector client and proxy. Remediation is available by upgrading affected packages to version 0.14.1.

CVE-2025-49596 at a Glance

CVE Identifier CVE-2025-49596
GHSA Identifier GHSA-7f8r-222p-6f5g
Severity CRITICAL
CVSS v3.1 Base Score N/A
CWE Classification CWE-306: Missing Authentication for Critical Function
Affected Product @modelcontextprotocol/inspector
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2025-49596

To remediate this vulnerability, upgrade all affected @modelcontextprotocol/inspector dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

@modelcontextprotocol/inspector fixed: 0.14.1 
npm install @modelcontextprotocol/inspector@0.14.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls @modelcontextprotocol/inspector

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2025-49596, inspect your project dependencies using npm:

npm ls @modelcontextprotocol/inspector

Analyze the terminal output to locate any version of @modelcontextprotocol/inspector in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.14.1), your application is affected.

Note: The npm ls @modelcontextprotocol/inspector command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-306: Missing Authentication for Critical Function, where the product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources. In @modelcontextprotocol/inspector, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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. Credit: Rémy Marot <bughunters@tenable.com>

CVE-2025-49596 Affected @modelcontextprotocol/inspector Versions

1 component(s)
Fixed Versions:
0.14.1
Product / Package Ecosystem Affected Versions Fixed Version
@modelcontextprotocol/inspector
npm/@modelcontextprotocol/inspector
npm
< 0.14.1
0.14.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/modelcontextprotocol/inspector/security/advisories/GHSA-7f8r-222p-6f5g
NVD — CVE-2025-49596 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-49596
Security Fix Commit FIX COMMIT
https://github.com/modelcontextprotocol/inspector/commit/50df0e1ec488f3983740b4d28d2a968f12eb8979
@modelcontextprotocol/inspector Source Repository REPOSITORY
https://github.com/modelcontextprotocol/inspector
thenewstack.io/mcp-vulnerability-e... WEB
https://thenewstack.io/mcp-vulnerability-exposes-the-ai-untrusted-code-crisis
@modelcontextprotocol/inspector Security Information SECURITY
https://www.oligo.security/blog/critical-rce-vulnerability-in-anthropic-mcp-inspector-cve-2025-49596

Frequently Asked Questions

What is CVE-2025-49596?
CVE-2025-49596 is a security vulnerability in @modelcontextprotocol/inspector involving MCP Inspector proxy server lacks authentication between the Inspector client and proxy under CWE-306: Missing Authentication for Critical Function.
Which @modelcontextprotocol/inspector versions are affected?
Affected versions include releases prior to 0.14.1 across affected packages: @modelcontextprotocol/inspector.
What version fixes CVE-2025-49596?
Upgrading to 0.14.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @modelcontextprotocol/inspector affected?
Yes, @modelcontextprotocol/inspector is affected in releases prior to 0.14.1. Upgrade your dependency to 0.14.1 or later.
What CWE is associated with CVE-2025-49596?
CVE-2025-49596 is classified under CWE-306: Missing Authentication for Critical Function (The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.).
How can I check npm dependencies for CVE-2025-49596?
Run the dependency tree command: 'npm ls @modelcontextprotocol/inspector'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-7f8r-222p-6f5g",
  "modified" : "2025-07-09T20:18:37Z",
  "published" : "2025-06-13T22:15:26Z",
  "aliases" : [ "CVE-2025-49596" ],
  "summary" : "MCP Inspector proxy server lacks authentication between the Inspector client and proxy",
  "details" : "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.\n\nCredit: Rémy Marot <bughunters@tenable.com>",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@modelcontextprotocol/inspector"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.14.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/modelcontextprotocol/inspector/security/advisories/GHSA-7f8r-222p-6f5g"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-49596"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/modelcontextprotocol/inspector/commit/50df0e1ec488f3983740b4d28d2a968f12eb8979"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/modelcontextprotocol/inspector"
  }, {
    "type" : "WEB",
    "url" : "https://thenewstack.io/mcp-vulnerability-exposes-the-ai-untrusted-code-crisis"
  }, {
    "type" : "WEB",
    "url" : "https://www.oligo.security/blog/critical-rce-vulnerability-in-anthropic-mcp-inspector-cve-2025-49596"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-306" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-06-13T22:15:26Z",
    "nvd_published_at" : "2025-06-13T20:15:23Z"
  }
}