Note that “Cross-site Scripting” is in the name as well as breakdown of different types of XSS in the “Extended Description”. Also, under CWE-79’s title, it says “Usage for Mapping: Allowed (this CWE ID could be used to map to real-world vulnerabilities), as well as “Abstraction: Base”.
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