CEF version was not updated on any UE4 branch.
For anyone interested, here is a q&d workaround to fake your User-Agent.
You mat add in UE4 CEFBrowserHandler
CefRequestHandler::ReturnValue MainHandler::OnBeforeResourceLoad(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefRequest> request, CefRefPtr<CefRequestCallback> callback)
HeaderMap.erase("User-Agent");
std::string latestChrome = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.132 Safari/537.36";
HeaderMap.insert(std::pair<CefString, CefString>(TCHAR_TO_WCHAR(TEXT("User-Agent")), latestChrome));