Nest has a Fastify URL Encoding Middleware Bypass (TOCTOU)

Nest is a framework for building scalable Node.js server-side applications. Versions prior to 11.1.11 have a Fastify URL encoding middleware bypass. A NestJS application is vulnerable if it uses @nestjs/platform-fastify; relies on NestMiddleware (via MiddlewareConsumer) for security checks (authentication, authorization, etc.), or through app.use(); and applies middleware to specific routes using string paths or controllers (e.g., .forRoutes('admin')). Exploitation can result in unauthenticated users accessing protected routes, restricted administrative endpoints becoming accessible to lower-privileged users, and/or middleware performing sanitization or validation being skipped. This issue is patched in @nestjs/platform-fastify@11.1.11.