Node.js Security Best Practices

Security is a habit applied at every layer

Security isn’t a feature you bolt on; it’s a set of habits applied across your code, dependencies, and configuration. These practices block the most common Node.js vulnerabilities.

Validate and Sanitise All Input

Never trust client data. Validate request bodies, params, and query strings against a schema, and reject anything unexpected:

import { z } from 'zod';
const Schema = z.object({ email: z.string().email(), age: z.number().int() });
const data = Schema.parse(req.body); // throws on invalid input

Common Threats and Defences

Threat Defence
Injection (SQL/NoSQL) Parameterised queries, never string concat
XSS Escape output, set a Content-Security-Policy
Secrets in code Env vars / secret managers, never commit keys
Brute force Rate limiting and account lockout

Secure headers and dependency hygiene close common gaps

Dependency and Secret Hygiene

  1. Run npm audit and patch known vulnerabilities promptly.
  2. Keep secrets in environment variables or a vault — and rotate them.
  3. Pin and review dependencies; a compromised package runs with your privileges.

Harden the HTTP Layer

  • Use helmet to set secure headers (HSTS, X-Content-Type-Options).
  • Enforce HTTPS and httpOnly, secure, sameSite cookies.
  • Apply rate limiting and sensible body-size limits.

Assume every input is hostile and every dependency could be compromised. Defence in depth does the rest.

What to Learn Next

  • Authentication and authorization patterns done right
  • OWASP Top 10 for web applications
  • Supply-chain security and SBOMs

Arivanandhan Chitheshwaran