CVE-2025-25299
Description
CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. During a recent internal audit, a Cross-Site Scripting (XSS) vulnerability was discovered in the CKEditor 5 real-time collaboration package. This vulnerability affects user markers, which represent users' positions within the document. It can lead to unauthorized JavaScript code execution, which might happen with a very specific editor and token endpoint configuration. This vulnerability affects only installations with Real-time collaborative editing enabled. The problem has been recognized and patched. The fix is available in version 44.2.1 (and above). Users are advised to upgrade. There are no known workarounds for this vulnerability.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
@ckeditor/ckeditor5-real-time-collaborationnpm | >= 41.3.0, < 44.2.1 | 44.2.1 |
ckeditor5-premium-featuresnpm | >= 42.0.0, < 44.2.1 | 44.2.1 |
Patches
14e45febe430bVulnerability mechanics
Generated by null/stub on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
6- github.com/advisories/GHSA-j3mm-wmfm-mwvhghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2025-25299ghsaADVISORY
- ckeditor.com/docs/ckeditor5/latest/features/collaboration/real-time-collaboration/real-time-collaboration.htmlnvdWEB
- ckeditor.com/docs/ckeditor5/latest/features/collaboration/real-time-collaboration/real-time-collaboration.htmlghsaWEB
- github.com/ckeditor/ckeditor5/releases/tag/v44.2.1nvdWEB
- github.com/ckeditor/ckeditor5/security/advisories/GHSA-j3mm-wmfm-mwvhnvdWEB
News mentions
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