TinyMCE Cross-Site Scripting (XSS) vulnerability using sanitization bypass through nested SVGs
Impact
TinyMCE 6.8.x contains an XSS vulnerability caused by improper SVG namespace scope handling in the sanitizer. A crafted payload using nested <svg> elements can bypass attribute sanitization and execute arbitrary JavaScript.
Patches
This issue affects TinyMCE 6.8.x-7.0.x. The vulnerability is fixed in TinyMCE 7.1.0 and later.
Workarounds
No official workaround available.
Acknowledgements
Tiny thanks maple3142 (https://maple3142.net) of DEVCORE for their help identifying this vulnerability.
References
Fix introduced in TinyMCE 7.1.0 though a rewrite of code causing the vulnerability.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | tinymce/tinymce | >= 6.8.0, < 7.1.0 | 7.1.0 |
| npm package | tinymce | >= 6.8.0, < 7.1.0 | 7.1.0 |
| .NET (NuGet) | TinyMCE | >= 6.8.0, < 7.1.0 | 7.1.0 |
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-mh5m-5hw4-5c69 - CC BY 4.0
Vulnerability history: tinymce
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 20
- First → latest
- 01.2020 06.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 5
- Medium 14
- Low 1
Disclosures per year
- 2020: 3
- 2021: 5
- 2022: 1
- 2023: 3
- 2024: 4
- 2025: 0
- 2026: 4
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TinyMCE Cross-Site Scripting (XSS) vulnerability using sanitization bypass through nested SVGs this entry
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