Cross-Site Scripting (XSS) is a vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. To protect against XSS, it's essential to validate and sanitize all user input, use secure coding practices like output encoding, and implement security measures like Content Security Policy (CSP).

Check completed with warnings

Header	Value
X-XSS-Protection	1; mode=block

The header might contain unwanted values.

The 1; mode=block value activates the browser's built-in reflective XSS protection. This setting enables the XSS filtering feature in the browser. If a potential XSS attack is detected, the browser will try to sanitize the page by removing the malicious script, allowing the rest of the content to be displayed. If the header is set to "1; mode=block", the browser takes a stricter approach by blocking the entire page if an XSS attack is detected, instead of trying to clean it.