GHSA-6226-h7ff-ch6c
HIGHGHSA-6226-h7ff-ch6c is a high-severity (CVSS 7.6) Cross-site Scripting (XSS) vulnerability in ckeditor4. O3 Security confirms whether GHSA-6226-h7ff-ch6c is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Widget feature vulnerability allowing to execute JavaScript code using undo functionality
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
ckeditor4npmDescription
Affected packages
The vulnerability has been discovered in Widget plugin if used alongside Undo feature.
Impact
A potential vulnerability has been discovered in CKEditor 4 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 [email protected] 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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | ckeditor4 | ≥ 4.13.0&&< 4.16.2 | 4.16.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ckeditor4. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update ckeditor4 to 4.16.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6226-h7ff-ch6c is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-6226-h7ff-ch6c is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-6226-h7ff-ch6c. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Frequently Asked Questions
Is GHSA-6226-h7ff-ch6c in your dependencies?
O3 detects GHSA-6226-h7ff-ch6c across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.