Yeah, after a quick look I already found an XSS on a *.webex.com subdomain, but it only works in Internet Explorer and Edge because these browsers doesn't escap

Yeah, after a quick look I already found an XSS on a *.webex.com subdomain, but it only works in Internet Explorer and Edge because these browsers doesn't escape URLs, so it doesn't affect the Chrome or Firefox extensions but tells something about how secure these subdomains are (and the IE browsers).