staging.heyo.com XSS vulnerability

Vulnerable URL: http://staging.heyo.com/fbcontests/1/showentry/No1-Multi-Contest/1128286/%22'--!%3E%3CImage%0CSrcset%3DK%0COnerror%3Dconfirm%60OPENBUGBOUNTY%60%0C Details: Description| Value ---|--- Patched:| No Latest check for patch:| 04.08.2017 Vulnerability type:| XSS Vulnerability status:|...