Provide references for CVE-2021-21391.
Where can I find more information about CVE-2021-21391?
References are available at: https://www.npmjs.com/package/%40ckeditor/ckeditor5-markdown-gfm, https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-3rh3-wfr4-76mj, https://www.npmjs.com/package/%40ckeditor/ckeditor5-engine, https://www.npmjs.com/package/%40ckeditor/ckeditor5-font, https://www.npmjs.com/package/%40ckeditor/ckeditor5-image, https://www.npmjs.com/package/%40ckeditor/ckeditor5-list, https://www.npmjs.com/package/%40ckeditor/ckeditor5-media-embed, https://www.npmjs.com/package/%40ckeditor/ckeditor5-paste-from-office, https://www.npmjs.com/package/%40ckeditor/ckeditor5-widget.