CVE-2025-5505 GHSA: Missing Authentication on Self-Hosted HTTP MCP Endpoint in @arunks/deepseek-mcp-server

Vulnerability Overview Vulnerability Name: Missing Authentication on Self-Hosted HTTP MCP Endpoint Vulnerability ID: GHSA-72F5-6W86-7V3 Severity: Moderate (5.3 / 10) CVE ID: CVE-2025-5505 CWE ID: CWE-306 Description: The self-hosted HTTP transport in exposes the endpoint without any authentication. is called without setting , and no middleware protects this route, allowing any network-reachable client to use an unauthenticated request to obtain a valid MCP session identifier. In repro tests, unauthenticated clients were able to initialize sessions, enumerate tools, and invoke local tools without credentials. The same unauthenticated session also exposed , whose handler processes requests via the server-side . Affected Versions Affected Versions: Fixed Version: CVSS v3 Base Metrics: - Attack Vector: Network - Attack Complexity: Low - Privileges Required: None - User Interaction: None - Scope: Unchanged - Confidentiality: None - Integrity: None - Availability: Low Remediation 1. Require Authentication: Require authentication before creating an MCP session in self-hosted HTTP mode. At minimum, pass to in , or place equivalent authentication middleware or a reverse proxy before to prevent unauthenticated clients from reaching the branch. 2. Restrict Local Access: For deployments requiring only local access, bind to instead of in both and . The upstream currently exposes ; changing it to will reduce unintended exposure on multi-user or server host environments. Proof of Concept (POC) Step 1: Send an Unauthenticated Request Response: Step 2: Send an Unauthenticated Request Response: Step 3: Send an Unauthenticated Request Response:

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CVE-2025-5505 GHSA: Missing Authentication on Self-Hosted HTTP MCP Endpoint in @arunks/deepseek-mcp-server

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