XWiki is a generic wiki platform. In versions starting from 15.9-rc-1 to before 15.10.8 and from 16.0.0-rc-1 to before 16.2.0, the required rights analysis doesn't consider TextAreas with default content type. When editing a page, XWiki warns since version 15.9 when there is content on the page like a script macro that would gain more rights due to the editing. This analysis doesn't consider certain kinds of properties, allowing a user to put malicious scripts in there that will be executed after a user with script, admin, or programming rights edited the page. Such a malicious script could impact the confidentiality, integrity and availability of the whole XWiki installation. This issue has been patched in versions 15.10.8 and 16.2.0.
https://jira.xwiki.org/browse/XWIKI-22002
https://github.com/xwiki/xwiki-platform/security/advisories/GHSA-mvgm-3rw2-7j4r
https://github.com/xwiki/xwiki-platform/commit/153dbfa2ef1a7a0a644fe3f889684c6a8738c5fc