DuckDuckGo: DOM XSS on 50x.html page on proxy.duckduckgo.com

Hi, I read the report about DOM XSS on 50x.html page https://hackerone.com/reports/405191. I decided to check some other subdomains to be sure. This link still executes javascript: https://proxy.duckduckgo.com/50x.html?e=&atb=test%22/%3E%3Cimg%20src=x%20onerror=alert%27test%27;%3E The following...