Abstract: As the demand of using internet and our dependence on web application to perform our daily activities is increasing every day, protecting web application from getting attacked by cyber criminal’s becomes imperative. The most common type of attack on web applications is XSS. XSS is considered as a major growing web security threat. XSS attacks are the scripts that are embedded in a web page and are executed at the victim’s machine. The objective of this study is to perform a literature review on the studies conducted on prevention and detection of XSS vulnerability. Results suggest that research in this field is going on very actively but no study provided full solution to this problem. More focus should be given to hybrid techniques and techniques using probabilistic model for detection of XSS vulnerability.