XWiki Platform Wiki UI Main Wiki is a package for managing subwikis. Starting with version 5.3-milestone-2, XWiki Platform Wiki UI Main Wiki contains a possible cross-site scripting vector in the WikiManager.JoinWiki
wiki page related to the "requestJoin" field. The issue is patched in versions 12.10.11, 14.0-rc-1, 13.4.7, and 13.10.3. The easiest available workaround is to edit the wiki page WikiManager.JoinWiki
(with wiki editor) according to the suggestion provided in the GitHub Security Advisory.