XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. It is possible for a user without Script or Programming rights to craft a URL pointing to a page with arbitrary JavaScript. This requires social engineer to trick a user to follow the URL. This has been patched in XWiki 14.10.21, 15.5.5, 15.10.6 and 16.0.0.
https://jira.xwiki.org/browse/XWIKI-21810
https://github.com/xwiki/xwiki-platform/security/advisories/GHSA-wcg9-pgqv-xm5v
https://github.com/xwiki/xwiki-platform/commit/27eca8423fc1ad177518077a733076821268509c