HTML comments vulnerability allowing to execute JavaScript code
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.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | ckeditor/ckeditor | < 4.17.0 | 4.17.0 |
| npm package | ckeditor4 | < 4.17.0 | 4.17.0 |
References
- https://github.com/ckeditor/ckeditor4/security/advisories/GHSA-7h26-63m7-qhf2
- https://nvd.nist.gov/vuln/detail/CVE-2021-41165
- https://github.com/ckeditor/ckeditor4
- https://github.com/ckeditor/ckeditor4/blob/major/CHANGES.md#ckeditor-417
- https://www.drupal.org/sa-core-2021-011
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpujul2022.html
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:L- Weakness (CWE)
CWE-79- Platform
- Composer, npm
- Package
ckeditor/ckeditor, ckeditor4- Disclosed
- 17.11.2021
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-7h26-63m7-qhf2 - CC BY 4.0
Vulnerability history: ckeditor4
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 15
- First → latest
- 05.2021 08.2024
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 4
- Medium 11
Disclosures per year
- 2021: 8
- 2022: 2
- 2023: 0
- 2024: 5
- 2025: 0
- 2026: 0
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HTML comments vulnerability allowing to execute JavaScript code this entry
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