TinyMCE XSS vulnerability in notificationManager.open API
Impact
A cross-site scripting (XSS) vulnerability was discovered in TinyMCE’s Notification Manager API. The vulnerability exploits TinyMCE's unfiltered notification system, which is used in error handling. The conditions for this exploit requires carefully crafted malicious content to have been inserted into the editor and a notification to have been triggered.
When a notification was opened, the HTML within the text argument was displayed unfiltered in the notification. The vulnerability allowed arbitrary JavaScript execution when an notification presented in the TinyMCE UI for the current user. This issue could also be exploited by any integration which uses a TinyMCE notification to display unfiltered HTML content.
Patches
This vulnerability has been patched in TinyMCE 5.10.8 and TinyMCE 6.7.1 by ensuring that the HTML displayed in the notification is sanitized, preventing the exploit.
Fix
To avoid this vulnerability:
- Upgrade to TinyMCE 5.10.8 or higher for TinyMCE 5.x.
- Upgrade to TinyMCE 6.7.1 or higher for TinyMCE 6.x.
References
- https://tiny.cloud/docs/release-notes/release-notes5108/#securityfixes
- https://tiny.cloud/docs/tinymce/6/6.7.1-release-notes/#security-fixes
For more information
If you have any questions or comments about this advisory:
- Email us at infosec@tiny.cloud
- Open an issue in the TinyMCE repo
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | tinymce/tinymce | >= 6.0.0, < 6.7.1, < 5.10.8 | 6.7.1, 5.10.8 |
| npm package | tinymce | >= 6.0.0, < 6.7.1, < 5.10.8 | 6.7.1, 5.10.8 |
| .NET (NuGet) | TinyMCE | >= 6.0.0, < 6.7.1, < 5.10.8 | 6.7.1, 5.10.8 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N- Weakness (CWE)
CWE-79- Platform
- Composer, npm, .NET (NuGet)
- Package
tinymce/tinymce, tinymce, TinyMCE- Disclosed
- 19.10.2023
- Updated
- 11.10.2026 11:17
Sources and licenses
OSV / GitHub Advisory Database - GHSA-hgqx-r2hp-jr38 - 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 XSS vulnerability in notificationManager.open API this entry
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