Node.js Security Best Practices

What is Security Best Practices in Node.js?

Most Node security incidents come from a short list of causes: unvalidated input, secrets in the repository, missing authorisation checks, outdated dependencies and overly detailed error messages.

Security Best Practices example

import helmet from 'helmet';
import rateLimit from 'express-rate-limit';
import mongoSanitize from 'express-mongo-sanitize';

app.use(helmet());                                  // security headers
app.use(express.json({ limit: '100kb' }));          // cap body size
app.use(mongoSanitize());                           // strip $ and . from keys
app.use(rateLimit({ windowMs: 900000, max: 300 }));
app.disable('x-powered-by');                        // hide the framework

Key points to remember

• Validate every input with a schema at the API boundary.
• Keep secrets in environment variables and out of git — rotate anything ever committed.
• Run npm audit and keep dependencies patched.
• Return generic error messages to clients; log details server-side.
• Enforce HTTPS and set secure, httpOnly, sameSite cookie flags.
• Cap request body size to blunt denial-of-service attempts.
• Never run the application as root, in a container or otherwise.

Common mistakes with Security Best Practices

• Sending stack traces to clients, which reveals paths, versions and structure.
• Interpolating user input into shell commands or database queries.
• A .env file committed to a public repository — assume those credentials are compromised.