XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. In affected versions it's possible to guess if a user has an account on the wiki by using the "Forgot your password" form, even if the wiki is closed to guest users. This problem has been patched on XWiki 12.10.9, 13.4.1 and 13.6RC1. Users are advised yo update. There are no known workarounds for this issue.

Information exposure in xwiki-platform