A mismatch occurs because the middleware evaluates the raw request target to determine if path-scoped middleware should run, whereas the Fastify router resolves an absolute-form request target to its path before dispatching. This discrepancy allows a request using an absolute-form target to reach the route handler while skipping path-scoped middleware used for authentication, authorization, rate limiting, or auditing. An unauthenticated network attacker can exploit this behavior to bypass path-based access controls.