GHSA-6226-h7ff-ch6c

Widget feature vulnerability allowing to execute JavaScript code using undo functionality

### Affected packages The vulnerability has been discovered in [Widget](https://ckeditor.com/cke4/addon/clipboard) plugin if used alongside [Undo](https://ckeditor.com/cke4/addon/undo) feature. ### Impact A potential vulnerability has been discovered in CKEditor 4 [Widget](https://ckeditor.com/cke4/addon/widget) package. The vulnerability allowed to abuse undo functionality using malformed widget HTML, which could result in executing JavaScript code. It affects all users using the CKEditor 4 plugins listed above at version >= 4.13.0. ### Patches The problem has been recognized and patched. The fix will be available in version 4.16.2. ### For more information Email us at security@cksource.com if you have any questions or comments about this advisory. ### Acknowledgements The CKEditor 4 team would like to thank Anton Subbotin ([skavans](https://github.com/skavans)) for recognizing and reporting this vulnerability.