Currently, there is no way to select the parent of an element in CSS. But if there was a way to do it, it would be in either of the current CSS selectors specs:
Selectors Level 3 Spec
CSS 2.1 Selectors Spec
If you want to select a parent element then you will have to resort to JavaScript.
In the Selectors Level 4 Working draft, there is a method :has() which is pseudo-class that works the same as the jQuery implementation. As of 2019, this is still not supported by any browser.
Using :has() the original question could be solved with this:
li:has(> a.active) {
}