XWiki Commons are technical libraries common to several other top level XWiki projects. The Document script API returns directly a DocumentAuthors allowing to set any authors to the document, which in consequence can allow subsequent executions of scripts since this author is used for checking rights. The problem has been patched in XWiki 14.10 and 14.4.7 by returning a safe script API.

org.xwiki.platform:xwiki-platform-oldcore makes Incorrect Use of Privileged APIs with DocumentAuthors