GHSA-mw2c-vx6j-mg76
MEDIUMCKEditor4 Cross-site Scripting vulnerability in samples with enabled the preview feature
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
ckeditor4npmDescription
Affected packages
The vulnerability has been discovered in the samples that use the preview feature:
samples/old/**/*.htmlplugins/[plugin name]/samples/**/*.html
All integrators that use these samples in the production code can be affected.
Impact
A potential vulnerability has been discovered in one of CKEditor's 4 samples that are shipped with production code. The vulnerability allowed to execute JavaScript code by abusing the misconfigured preview feature. It affects all users using the CKEditor 4 at version < 4.24.0-lts with affected samples used in a production environment.
Patches
The problem has been recognized and patched. The fix will be available in version 4.24.0-lts.
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 Marcin Wyczechowski & Michał Majchrowicz AFINE Team for recognizing and reporting this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | ckeditor4 | all versions | 4.24.0-lts |
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 4.24.0-lts or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mw2c-vx6j-mg76 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-mw2c-vx6j-mg76 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-mw2c-vx6j-mg76. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-mw2c-vx6j-mg76 in your dependencies?
O3 detects GHSA-mw2c-vx6j-mg76 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.