Provide references for CVE-2021-39318.
Where can I find more information about CVE-2021-39318?
References are available at: https://www.wordfence.com/vulnerability-advisories/#CVE-2021-39318, https://plugins.trac.wordpress.org/browser/h5p-css-editor/tags/1.0/h5p-css-editor.php#L50.