CVE-2017-6536 (webpagetest)
Multiple Cross-Site Scripting (XSS) issues were discovered in webpagetest 3.0. The vulnerabilities exist due to insufficient filtration of user-supplied data (url, pssid) passed to the webpagetest-master/www/weblite.php URL. An attacker could execute arbitrary HTML and script code in a browser in the context of the vulnerable website.
Source: CVE-2017-6536 (webpagetest)