TinyMCE Cross-Site Scripting (XSS) vulnerability using media plugin `data-mce-object` injection
Published 5 Jun 2026 · Updated 10 Sept 2026
Affected packages
- Affected
- <=5.10.9
- Fixed in
- No fix released
- Affected
- >=6.0.0 <7.9.3
- Fixed in
- 7.9.3
npm install tinymce@7.9.3- Affected
- >=8.0.0 <8.5.1
- Fixed in
- 8.5.1
npm install tinymce@8.5.1- Affected
- <=5.10.9
- Fixed in
- No fix released
- Affected
- >=6.0.0 <7.9.3
- Fixed in
- 7.9.3
composer require tinymce/tinymce:^7.9.3- Affected
- >=8.0.0 <8.5.1
- Fixed in
- 8.5.1
composer require tinymce/tinymce:^8.5.1Details
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.
Is GHSA-vg35-5wq7-3x7w in any of your client repos?
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References
Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.