GHSA-wf8q-wvv8-p8jf: @samanhappy/mcphub: SSE Endpoint Accepts Arbitrary Username from URL Path Without Authentication, Enabling User Impersonation

A critical identity spoofing vulnerability in MCPHub allows any unauthenticated user to impersonate any other user — including administrators — on SSE (Server-Sent Events) and MCP transport endpoints. The server accepts a username from the URL path parameter and creates an internal user session without any database validation, token verification, or authentication check. The source code itself acknowledges this gap with a TODO comment.