The Next.js Security Checklist for AI-Generated Code

A recent audit of applications built with AI assistance revealed that over 91% contain security vulnerabilities, often because AI models prioritize popular coding patterns over secure ones. In the context of Next.js, AI frequently generates code that relies on insecure practices, such as using middleware as a primary security boundary, storing tokens in localStorage, or leaking secrets via public environment variables. This article provides a comprehensive 10-point security checklist to mitigate these risks. Key recommendations include verifying authentication at the data layer rather than relying on middleware, treating all 'use server' actions as public endpoints, and strictly avoiding client-side exposure of sensitive keys. The author emphasizes that while AI-generated code often functions correctly, it frequently lacks the necessary security architecture. Developers are urged to act as the final verification layer, ensuring that input validation, rate limiting, and proper secret management are implemented to protect against common exploits.