Roxy-WI is a web interface for managing Haproxy, Nginx, Apache and Keepalived servers. In versions 8.2.6.4 and prior, wrap_line (app/modules/common/common.py:181-186) and highlight_word (app/modules/common/common.py:188-192) build raw HTML by string concatenation with no escaping. The frontend (app/static/js/script.js, log-viewer paths) uses .html(data) / .append(data) to inject the response body. Anyone able to write a line into a managed HAProxy/Nginx access log (i.e. anyone who can send an HTTP request to the public LB) can land an <svg/onload=…> payload that executes when a Roxy-WI admin opens the log viewer. At time of publication, there are no publicly available patches.