Cross-Site Scripting
XSS
noun (acronym)Definition
A security vulnerability where an attacker injects malicious scripts into web pages viewed by other users. Prevented by escaping user-supplied output and using a Content Security Policy (CSP). Ranked in the OWASP Top 10.
In a sentence
"The XSS vulnerability allowed attackers to inject a script into comment fields, stealing session cookies from anyone who viewed the page."