Express.js Security Best Practices Guide

Set Secure HTTP Headers

Always use Helmet to set standard security headers.

• Enable X-Content-Type-Options to prevent MIME type sniffing
• Set X-Frame-Options to mitigate clickjacking attacks
• Configure Content-Security-Policy for resource loading restrictions

Input Validation

Use express-validator for robust input sanitization.

• Validate and sanitize all user inputs
• Use whitelisting instead of blacklisting
• Reject invalid data with proper error messages

Use Helmet

Helmet is a middleware that simplifies security header configuration.

const helmet = require('helmet');
app.use(helmet());

Rate Limiting

Implement rate limiting to prevent abuse. Check our guide on rate limiting for details.

• Use express-rate-limit middleware
• Set limits per IP address
• Block excessive requests with 429 status code

Secure Routing

Always validate routes and avoid exposing sensitive information.

• Use express.Router() for organized endpoints
• Avoid using res.sendFile() for sensitive files
• Implement proper authentication checks

CORS Configuration

Configure CORS headers correctly to prevent cross-origin attacks.

• Use cors middleware with strict origin policies
• Disable allowOrigin for untrusted domains
• Set maxAge for preflight requests

Password Handling

Always hash passwords using bcrypt.

const bcrypt = require('bcrypt');
bcrypt.hash(password, 10, (err, hash) => {
  // Store hash in database
});

Logging & Monitoring

Enable logging to track suspicious activity. Learn more about logging.

• Use morgan for HTTP request logging
• Monitor for unusual traffic patterns
• Set up alerts for potential security breaches

Regular Updates

Keep dependencies updated to patch vulnerabilities.

• Use npm audit to check for security issues
• Update Express.js and related packages regularly
• Monitor for new security advisories

For advanced security configurations, visit our security guide section.