GHSA-vg35-5wq7-3x7w TinyMCE Cross-Site Scripting (XSS) vulnerability using media plugin `data-mce-object` injection

• npm tinymce: <= 5.10.9 (no fix yet) • npm tinymce: >= 6.0.0, < 7.9.3 → fixed in 7.9.3 • npm tinymce: >= 8.0.0, < 8.5.1 → fixed in 8.5.1 • NuGet TinyMCE: <= 5.10.9 (no fix yet) • NuGet TinyMCE: >= 6.0.0, < 7.9.3 → fixed in 7.9.3 • NuGet TinyMCE: >= 8.0.0, < 8.5.1 → fixed in 8.5.1 • Packagist tinymce/tinymce: <= 5.10.9 (no fix yet) • Packagist tinymce/tinymce: >= 6.0.0, < 7.9.3 → fixed in 7.9.3 • Packagist tinymce/tinymce: >= 8.0.0, < 8.5.1 → fixed in 8.5.1

Impact 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. Patches This vulnerability has been patched in TinyMCE 8.5.1, TinyMCE 7.9.3 and TinyMCE 5.11.1 LTS by ensuring that, when using the media plugin, any content with `data-mce-object` and `data-mce-p-*` attributes are properly sanitized. Workarounds No official workaround available. Fix To avoid this vulnerability: • Upgrade to TinyMCE 8.5.1 or higher. • Upgrade to TinyMCE 7.9.3 or higher. • Upgrade to TinyMCE 5.11.1 LTS or higher for TinyMCE 5.x (only available as part of commercial long-term support contract). Acknowledgements Tiny thanks Aymane MAZGUITI and Ange Primiterra for their help identifying this vulnerability.