The vulnerability resides in MCPHub’s PUT /api/system-config endpoint. The handler performs no check on the user’s administrative status, relying only on generic authentication and a rate limiter. Consequently, any authenticated user, even a non‑administrator, can alter the global security configuration of the entire MCPHub deployment. This allows an attacker to modify authorization rules, compromise credential handling, or otherwise disrupt the security posture of all connected MCP servers. The weakness is an example of improper authorization (CWE‑269) and privilege escalation via insecure API design (CWE‑862).

The issue affects the MCPHub product from vendor samanhappy. All deployments using any version prior to 1.0.29 are vulnerable. Versions 1.0.29 and later contain the fix that enforces administrative checks on the system‑config endpoint.

The CVSS score of 8.8 classifies the flaw as high severity, indicating a significant impact if exploited. While no EPSS data is available, the lack of an authorization guard presents a clear and straightforward exploitation path for any authenticated user without administrative rights. Importantly, the vulnerability is not listed in CISA’s KEV catalog, but the severity and the nature of the flaw make it a strong candidate for targeted exploitation by attackers with legitimate access to the service. The attack vector is likely a normal web request from a non‑admin user, meaning that internal adversaries or compromised accounts pose a direct threat.