React's growing dominance in frontend development brings unique security challenges. While React provides built-in protections, developers must implement additional security measures to prevent XSS, CSRF, and other vulnerabilities. This comprehensive security checklist covers all critical areas to secure your React applications in 2025.

Critical Security Areas

🛡️XSS Prevention: Properly escape dynamic content and sanitize user inputs to prevent script injection attacks
🔒CSRF Protection: Implement token-based protection and secure cookie policies to prevent unauthorized actions
⚠️Safe DOM Manipulation: Avoid dangerous patterns like dangerouslySetInnerHTML without proper sanitization
📦Dependency Security: Regular auditing and updates of third-party packages to patch known vulnerabilities

1. Cross-Site Scripting (XSS) Prevention

XSS attacks are among the most common vulnerabilities in React applications. While React provides automatic escaping in JSX, developers must understand when and how additional protection is needed according to the OWASP Top 10 [1].

React Built-in XSS Protection

Automatic Escaping in JSX

React automatically escapes all values when using JSX curly braces, providing protection against most XSS attacks:

// Safe: React automatically escapes this content
const userInput = "<script>alert('XSS')</script>";
return <div>{userInput}</div>;
// Renders: &lt;script&gt;alert('XSS')&lt;/script&gt;

Dangerous Patterns to Avoid

High-Risk Code Patterns

❌ Unsafe: dangerouslySetInnerHTML

// DANGEROUS: Never do this with user input
const createMarkup = (html) => ({ __html: html });
const userContent = "<img src=x onerror=alert('XSS')>";
return <div dangerouslySetInnerHTML={createMarkup(userContent)} />;

The dangerouslySetInnerHTML property bypasses React automatic escaping according to React documentation [2].

Safe HTML Rendering with Sanitization

Using DOMPurify for Safe HTML

When you must render HTML content, use a sanitization library like DOMPurify [3]:

import DOMPurify from 'dompurify';

// Safe: Sanitize HTML before rendering
const SafeHtmlComponent = ({ htmlContent }) => {
  const sanitizedHtml = DOMPurify.sanitize(htmlContent, {
    ALLOWED_TAGS: ['b', 'i', 'em', 'strong', 'a', 'p', 'br'],
    ALLOWED_ATTR: ['href', 'target'],
    ALLOW_DATA_ATTR: false
  });

  return (
    <div
      dangerouslySetInnerHTML={{ __html: sanitizedHtml }}
    />
  );
};

2. Cross-Site Request Forgery (CSRF) Protection

CSRF attacks trick authenticated users into performing unintended actions. React applications must implement CSRF protection as recommended by OWASP [4].

CSRF Token Implementation

Token-Based CSRF Protection

// CSRF token management
const CSRFContext = createContext();

export const CSRFProvider = ({ children }) => {
  const [csrfToken, setCsrfToken] = useState('');

  useEffect(() => {
    fetch('/api/csrf-token', { credentials: 'include' })
      .then(response => response.json())
      .then(data => setCsrfToken(data.token));
  }, []);

  return (
    <CSRFContext.Provider value={csrfToken}>
      {children}
    </CSRFContext.Provider>
  );
};

3. Content Security Policy (CSP)

A properly configured Content Security Policy provides strong defense against XSS attacks according to Mozilla CSP documentation [5].

Basic CSP Configuration

Content-Security-Policy: 
  default-src 'self';
  script-src 'self';
  style-src 'self' 'unsafe-inline';
  img-src 'self' data: https:;

4. Security Checklist Summary

Complete Security Verification List

🛡️ XSS Prevention

☐ Avoid dangerouslySetInnerHTML without sanitization
☐ Use DOMPurify for HTML content sanitization
☐ Validate and sanitize all user inputs
☐ Implement Content Security Policy
☐ Escape dynamic content in JSX

🔒 CSRF Protection

☐ Implement CSRF tokens for state-changing requests
☐ Configure SameSite cookies properly
☐ Use httpOnly cookies for sensitive data
☐ Validate referrer headers

📦 Dependency Security

☐ Run npm audit regularly
☐ Keep React and dependencies updated
☐ Use security scanning tools
☐ Review package permissions

🔐 Authentication

☐ Store tokens in httpOnly cookies
☐ Implement proper session management
☐ Use HTTPS for all authentication
☐ Implement token refresh mechanisms

References

[1] OWASP Top 10 Web Application Security Risks
[2] React Documentation: dangerouslySetInnerHTML
[3] DOMPurify: XSS sanitizer library
[4] OWASP CSRF Prevention Cheat Sheet
[5] MDN: Content Security Policy

React Security Checklist: Complete Guide for 2025