An issue was discovered in Munkireport before 5.3.0.3923. An unauthenticated actor can send a custom XSS payload through the /report/broken_client endpoint. The payload will be executed by any authenticated users browsing the application. This concerns app/views/listings/default.php.
https://github.com/munkireport/munkireport-php/wiki/20200309-XSS-vulnerability