HighGHSA-7h26-63m7-qhf2BIT-drupal-2021-41165CVE-2021-41165

HTML comments vulnerability allowing to execute JavaScript code

Published 17 Nov 2021 · Updated 8 Jul 2026

Affected packages

ckeditor4npm

Affected: <4.17.0
Fixed in: 4.17.0

Update to the fixed version for your release line, for example:npm install ckeditor4@4.17.0

ckeditor/ckeditorComposer

Affected: <4.17.0
Fixed in: 4.17.0

Update to the fixed version for your release line, for example:composer require ckeditor/ckeditor:^4.17.0

Details

Affected packages

The vulnerability has been discovered in the core HTML processing module and may affect all plugins used by CKEditor 4.

Impact

A potential vulnerability has been discovered in CKEditor 4 HTML processing core module. The vulnerability allowed to inject malformed comments HTML bypassing content sanitization, which could result in executing JavaScript code. It affects all users using the CKEditor 4 at version < 4.17.0.

Patches

The problem has been recognized and patched. The fix will be available in version 4.17.0.

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 William Bowling (wbowling) 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.