XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Starting with the introduction of attachment move support in version 14.0-rc-1 and prior to versions 14.4.8, 14.10.4, and 15.0-rc-1, an attacker with edit access on any document (can be the user profile which is editable by default) can move any attachment of any other document to this attacker-controlled document. This allows the attacker to access and possibly publish any attachment of which the name is known, regardless if the attacker has view or edit rights on the source document of this attachment. Further, the attachment is deleted from the source document. This vulnerability has been patched in XWiki 14.4.8, 14.10.4, and 15.0 RC1. There is no workaround apart from upgrading to a fixed version.