Remember, Base and Variant weaknesses are the preferred weakness abstraction for root cause mapping.
If you scroll down the page a bit, you can see a list of CWE-79’s “Relationships”, which may be worth exploring to identify if a different but related weakness might be more suitable for your vulnerability root cause mapping. There are several XSS-related CWEs, as highlighted by Parent, Child, PeerOf, CanFollow, and CanPrecede relationship types. Parent and Child represent direct relationships to CWE-79, whereas the other types can be at the same level or lead to other weaknesses. Here is an example of what that looks like:
CWE-79 Relationships
The CWE “View” Methods