XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Starting in version 5.0-milestone-1 and prior to versions 14.4.8, 14.10.4, and 15.0-rc-1, tags from pages not viewable to the current user are leaked by the tags API. This information can also be exploited to infer the document reference of non-viewable pages. This vulnerability has been patched in XWiki 14.4.8, 14.10.4, and 15.0-rc-1.