A high-severity authorization bypass in MCPHub allows authenticated users to access unauthorized servers, potentially leading to unauthorized data exposure and manipulation.

This is an incorrect authorization flaw (CWE-863) where the isBearerKeyAllowedForRequest function fails to validate bearer key scopes correctly for grouped routes. An attacker with low-level privileges can gain unauthorized access to servers within a group that were not explicitly included in their key's scope.

The vulnerability carries a CVSS score of 8.1, reflecting a high risk of unauthorized information disclosure and data modification. By bypassing group-level access controls, an attacker can access sensitive API endpoints and data stores they are not authorized to view or modify, resulting in significant security and compliance risks for the organization.

Immediate Action: Upgrade to MCPHub version 1.0.31 or later to implement the corrected authorization logic.

Proactive Monitoring: Review system and access logs for unusual patterns of cross-server requests or unauthorized access attempts to sensitive MCP endpoints.

Compensating Controls: If immediate patching is not feasible, restrict network access to the MCPHub management interface and enforce strict identity provider scoping to limit the impact of compromised bearer keys.

Public Exploit Available: Unknown

Given the high CVSS score and the nature of the authorization bypass, immediate remediation is required. Organizations using MCPHub should prioritize the update to version 1.0.31 to prevent potential unauthorized access to sensitive server infrastructure.