Security

Security vulnerabilities can destroy your app, your users, and your reputation overnight. This guide covers the most critical web security threats — XSS, SQL Injection, CSRF, broken auth — and exactly how to prevent them with code examples.

Server A issues a JWT. Server B validates it 2 seconds later but thinks the token was issued in the future — invalid. Or a token that should be expired is still accepted because the validating server's clock is 5 minutes behind. Clock skew causes authentication failures and security holes.