TinyMCE Cross-Site Scripting (XSS) vulnerability in handling external SVG files through Object or Embed elements
Impact
A cross-site scripting (XSS) vulnerability was discovered in TinyMCE’s content loading and content inserting code. A SVG image could be loaded though an object or embed element and that image could potentially contain a XSS payload.
Fix
TinyMCE 6.8.1 introduced a new convert_unsafe_embeds option to automatically convert object and embed elements respective of their type attribute. From TinyMCE 7.0.0 onwards, the convert_unsafe_embeds option is enabled by default.
Workarounds
If you are using TinyMCE 6.8.1 or higher, set convert_unsafe_embeds to true. For any earlier versions, a custom NodeFilter is recommended to remove or modify any object or embed elements. This can be added using the editor.parser.addNodeFilter and editor.serializer.addNodeFilter APIs.
Acknowledgements
Tiny Technologies would like to thank Toni Huttunen of Fraktal Oy for discovering this vulnerability.
References
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | tinymce/tinymce | < 7.0.0 | 7.0.0 |
| npm package | tinymce | < 7.0.0 | 7.0.0 |
| .NET (NuGet) | TinyMCE | < 7.0.0 | 7.0.0 |
References
- https://github.com/tinymce/tinymce/security/advisories/GHSA-5359-pvf2-pw78
- https://nvd.nist.gov/vuln/detail/CVE-2024-29881
- https://github.com/tinymce/tinymce/commit/bcdea2ad14e3c2cea40743fb48c63bba067ae6d1
- https://github.com/tinymce/tinymce
- https://www.tiny.cloud/docs/tinymce/6/6.8.1-release-notes/#new-convert_unsafe_embeds-option-that-controls-whether-object-and-embed-elements-will-be-converted-to-more-restrictive-alternatives-namely-img-for-image-mime-types-video-for-video-mime-types-audio-audio-mime-types-or-iframe-for-other-or-unspecified-mime-types
- https://www.tiny.cloud/docs/tinymce/7/7.0-release-notes/#convert_unsafe_embeds-editor-option-is-now-defaulted-to-true
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N- Weakness (CWE)
CWE-79- Platform
- Composer, npm, .NET (NuGet)
- Package
tinymce/tinymce, tinymce, TinyMCE- Disclosed
- 26.03.2024
- Updated
- 11.10.2026 11:23
Sources and licenses
OSV / GitHub Advisory Database - GHSA-5359-pvf2-pw78 - CC BY 4.0
Vulnerability history: TinyMCE
All published vulnerabilities of this package (.NET (NuGet)), 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 in handling external SVG files through Object or Embed elements this entry
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