Preventing Cross-Site Scripting (XSS) in Node.js Applications

Web security is a critical part of modern application development, yet Cross-Site Scripting (XSS) remains one of the most common vulnerabilities threatening user data. If your application handles user input, it is potentially at risk of malicious script injection. This text-only course guides you through the core mechanics of XSS attacks and equips you with the practical skills to defend your Node.js applications. You will learn to transition from writing vulnerable code to implementing robust, production-ready security layers. What you'll learn: - Understand the core concepts of Cross-Site Scripting, including Stored, Reflected, and DOM-based XSS. - Identify common entry points and vulnerability patterns in Node.js and Express applications. - Implement robust input sanitization and output encoding using modern libraries. - Configure secure HTTP headers and Content Security Policy (CSP) using Helmet middleware. - Secure session cookies and authentication tokens against malicious script access. - Apply automated security scanning tools to detect vulnerabilities early in your development workflow. You will start with fundamental security concepts and definitions before moving on to practical, step-by-step code examples. Through clear written explanations, you will explore how to analyze vulnerable code and refactor it using industry-standard security practices. This course is designed for beginner-to-intermediate Node.js developers and web developers who want to build secure applications. No prior cybersecurity experience is required. Start reading today to build safer, more resilient web applications.