TinyMCE is an open source rich text editor. Prior to 5.11.1, 7.9.3, and 8.5.1, there is a stored XSS vulnerability in the media plugin. Attackers can inject malicious scripts via crafted data-mce-* attributes, which are executed when content is rendered. Impacts users of TinyMCE with the media plugin enabled. This vulnerability is fixed in 5.11.1, 7.9.3, and 8.5.1.
https://www.tiny.cloud/docs/tinymce/8/8.5.1-release-notes/#overview
https://www.tiny.cloud/docs/tinymce/7/7.9.3-release-notes/#overview
https://github.com/tinymce/tinymce/security/advisories/GHSA-vg35-5wq7-3x7w