DOM-Based Cross-Site Scripting (XSS) is a type of security vulnerability that occurs when a web application allows users to manipulate the Document Object Model (DOM) in a way that executes malicious scripts. This happens when client-side scripts, such as JavaScript, read data from the URL or user input without proper validation or sanitization, leading to unintended script execution. In this attack, the malicious code is executed in the user's browser rather than on the server. This can result in unauthorized access to sensitive information, such as cookies or session tokens, potentially compromising user accounts and privacy. Proper coding practices and security measures are essential to prevent DOM-Based XSS.