XSS, or Cross-Site Scripting, is a web security vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. It exploits the fact that browsers cannot distinguish between script that's part of the website and script that's been maliciously injected into the page. The consequences range from minor annoyance to significant security breaches, such as stealing cookies, session tokens, or even hijacking user sessions. Preventing XSS typically involves sanitizing data input by users on web applications.
