XWiki describes itself as "The Advanced Open-Source Enterprise Wiki" and considers itself an alternative to Confluence and MediaWiki. In February, XWiki released an advisory (and patch) for an arbitrary remote code execution vulnerability. Affected was the SolrSearch component, which any user, even with minimal "Guest" privileges, can use. The advisory included PoC code, so it is a bit odd that it took so long for the vulnerability to be widely exploited.