Django CMS 3.7.3 does not validate the plugin_type parameter while generating error messages for an invalid plugin type, resulting in a Cross Site Scripting (XSS) vulnerability. The vulnerability allows an attacker to execute arbitrary JavaScript code in the web browser of the affected user.
https://www.django-cms.org/en/blog/2020/07/22/django-cms-security-updates-1/
https://sahildhar.github.io/blogpost/Django-CMS-Reflected-XSS-Vulnerability/