File uploads may seem simple, but they're one of the most common attack vectors in modern web and mobile applications. A single insecure upload endpoint can expose your system to malware, remote code execution, storage abuse, sensitive data leaks, or even complete server compromise.
Whether you're building a SaaS platform, mobile app, AI product, or internal business tool, secure file uploads should be part of your security strategy from day one.
Here are 12 essential security checks every developer should implement before deploying a file upload feature.
Never trust file extensions alone—attackers can easily rename malicious files.
Always validate on the server using:
