WikiDiscover is an extension designed for use with a CreateWiki managed farm to display wikis. On Special:WikiDiscover, the `Language::date` function is used when making the human-readable timestamp for inclusion on the wiki_creation column. This function uses interface messages to translate the names of months and days. It uses the `->text()` output mode, returning unescaped interface messages. Since the output is not escaped later, the unescaped interface message is included on the output, resulting in an XSS vulnerability. Exploiting this on-wiki requires the `(editinterface)` right. This vulnerability has been addressed in commit `267e763a0`. Users are advised to update their installations. There are no known workarounds for this vulnerability.