CVE-2025-25299
Cross-site scripting (XSS) in the CKEditor 5 real-time collaboration package
Impact
### Impact During a recent internal audit, we identified a Cross-Site Scripting (XSS) vulnerability in the CKEditor 5 real-time collaboration package. This vulnerability can lead to unauthorized JavaScript code execution and affects user markers, which represent users' positions within the document. This vulnerability affects only installations with [Real-time collaborative editing](https://ckeditor.com/docs/ckeditor5/latest/features/collaboration/real-time-collaboration/real-time-collaboration.html) enabled. ### Patches The problem has been recognized and patched. The fix will be available in version 44.2.1 (and above). ### For more information Email us at [security@cksource.com](mailto:security@cksource.com) if you have any questions or comments about this advisory.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @ckeditor/ckeditor5-real-time-collaboration | >= 41.3.0, <= 44.2.0 | 44.2.1 |
| npm | ckeditor5-premium-features | >= 42.0.0, < 44.2.0 | 44.2.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://ckeditor.com/docs/ckeditor5/latest/features/collaboration/real-time-collaboration/real-time-collaboration.html
- https://github.com/ckeditor/ckeditor5/releases/tag/v44.2.1
- https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-j3mm-wmfm-mwvh
- https://github.com/advisories/GHSA-j3mm-wmfm-mwvh
- https://ckeditor.com/docs/ckeditor5/latest/features/collaboration/real-time-collaboration/real-time-collaboration.html?docId=ee1dca024c9b4e44aef039f99ebe6c664
- https://nvd.nist.gov/vuln/detail/CVE-2025-25299