MediumGHSA-7889-rm5j-hpggCVE-2021-32809

Clipboard feature vulnerability allowing to inject arbitrary HTML into the editor using paste functionality

Published 23 Aug 2021 · Updated 8 Jul 2026

Affected package

ckeditor4npm

Affected: >=4.5.2 <4.16.2
Fixed in: 4.16.2

Update to the fixed version for your release line, for example:npm install ckeditor4@4.16.2

Details

Affected packages

The vulnerability has been discovered in clipboard plugin. All plugins with clipboard plugin dependency are affected:

Impact

A potential vulnerability has been discovered in CKEditor 4 Clipboard package. The vulnerability allowed to abuse paste functionality using malformed HTML, which could result in injecting arbitrary HTML into the editor. It affects all users using the CKEditor 4 plugins listed above at version >= 4.5.2.

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) for recognizing and reporting this vulnerability.

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References

Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.