Security in React 19

Security is critical for protecting user data and application integrity. Follow these best practices in React 19 projects:

Input Validation & Sanitization

• Always validate and sanitize user input on both client and server.
• Use libraries like DOMPurify for sanitizing HTML if rendering user content.

Preventing XSS

• Never dangerously set inner HTML with untrusted content (dangerouslySetInnerHTML).
• Escape dynamic content in JSX.
• Use Content Security Policy (CSP) headers on the server.

Preventing CSRF

• Use CSRF tokens for state-changing requests to APIs.
• Prefer same-site cookies and secure headers.

Authentication & Authorization

• Use secure authentication flows (OAuth, JWT, etc.).
• Protect routes with guards and role checks.

Secure Communication

• Always use HTTPS for all API and asset requests.
• Store sensitive data securely (never in localStorage if possible).

Dependency Management

• Keep dependencies up to date to avoid known vulnerabilities.
• Audit packages regularly with npm audit or yarn audit.

Example: Sanitizing HTML

import DOMPurify from 'dompurify';
const safeHtml = DOMPurify.sanitize(userInput);

References

• OWASP Top 10
• React Security Guide
• DOMPurify