TinyMCE Cross-Site Scripting (XSS) vulnerability using media plugin `data-mce-object` injection
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.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | tinymce/tinymce | <= 5.10.9, >= 6.0.0, < 7.9.3, >= 8.0.0, < 8.5.1 | 7.9.3, 8.5.1 |
| npm package | tinymce | <= 5.10.9, >= 6.0.0, < 7.9.3, >= 8.0.0, < 8.5.1 | 7.9.3, 8.5.1 |
| .NET (NuGet) | TinyMCE | <= 5.10.9, >= 6.0.0, < 7.9.3, >= 8.0.0, < 8.5.1 | 7.9.3, 8.5.1 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N- Weakness (CWE)
CWE-79- Platform
- Composer, npm, .NET (NuGet)
- Package
tinymce/tinymce, tinymce, TinyMCE- Disclosed
- 05.06.2026
- Updated
- 11.10.2026 11:23
Sources and licenses
OSV / GitHub Advisory Database - GHSA-vg35-5wq7-3x7w - CC BY 4.0
Vulnerability history: tinymce/tinymce
All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 15
- First → latest
- 01.2021 06.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 4
- Medium 11
Disclosures per year
- 2021: 3
- 2022: 1
- 2023: 3
- 2024: 4
- 2025: 0
- 2026: 4
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TinyMCE Cross-Site Scripting (XSS) vulnerability using media plugin `data-mce-object` injection this entry
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