CBV is just a shortcut from Class-based views, which is a generic term for any view in Django that is defined as a class in your code, especially one inheriting from django.views.View.
So the CBV Mixin is just any mixin that can be used in a Class-based view.
I was reading about the Django UserPassesTestMixinmixin, and I came across the term CBV Mixin. What is this, and how is it useful? Is a CBV Mixin a general type of mixins, and are there CBV mixins in any other framework apart from Django?
What is a CBV mixin in Django?