XSS is a breach in the security of a web application or site, which makes it easier for a hacker to embed their malicious code. JavaScript was the first and primary language in which scripts were created. However, XSS may have used other resources, such as HTML, Flash, or something else. Most XSS attacks are performed in JavaScript. But to implement malicious JS, the user needs to exploit the vulnerability of the page code on the client or server side. You can also use the Client Security Policy (CSP) to prevent using XSS in current views.