Roundup 1.6 allows XSS via the URI because frontends/roundup.cgi and roundup/cgi/wsgi_handler.py mishandle 404 errors.
https://www.openwall.com/lists/oss-security/2019/04/05/1
https://lists.debian.org/debian-lts-announce/2019/04/msg00009.html
https://github.com/python/bugs.python.org/issues/34