Nest is a framework for building scalable Node.js server-side applications. Prior to 11.1.24, an authentication bypass vulnerability exists in @nestjs/platform-fastify. When middleware is registered through NestJS's MiddlewareConsumer.forRoutes() API on the Fastify adapter, an unauthenticated client can bypass the Nest middleware registered for that route by simply appending a trailing slash (/) to the request URL. This bypass works on the default Fastify adapter configuration. This vulnerability is fixed in 11.1.24.