Npm · @Fastify/Middie · CVE-2026-85184
**Name of the Vulnerable Software and Affected Versions**
@fastify/middie versions 9.1.0 through 9.3.3
**Description**
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.
**Recommendations**
Update @fastify/middie to version 9.3.4 or later.
As a workaround, enforce authentication using a Fastify hook such as `preHandler()`.