CKEditor: Cross-site scripting (XSS) in the engine package

### Impact A Cross-Site Scripting (XSS) vulnerability has been discovered in the CKEditor 5 engine. This vulnerability could be triggered by inserting specially crafted markup under a specific General HTML Support configuration that allows inserting objects, leading to unauthorized JavaScript code execution in a browser context isolated from the origin of the application embedding the editor. This vulnerability affects only installations where General HTML Support is enabled and configured to allow the affected HTML content. ### Patches The problem has been recognized and patched. The fix will be available in version `48.5.1` (and above) and `47.7.4` (LTS). ### For more information Email us at [[email protected]](mailto:[email protected]) if you have any questions or comments about this advisory.

Source published

27 Oct 2026 21:05:13 UTC

Source modified

27 Oct 2026 21:15:03 UTC

Observed here

27 Oct 2026 21:46:44 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N

Publisher rating · LOW