How severe is GHSA-j3mm-wmfm-mwvh?

No CVSS score has been assigned to GHSA-j3mm-wmfm-mwvh yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-j3mm-wmfm-mwvh?

GHSA-j3mm-wmfm-mwvh affects the following packages: @ckeditor/ckeditor5-real-time-collaboration (npm), ckeditor5-premium-features (npm). Ecosystems affected: npm.

How do I fix GHSA-j3mm-wmfm-mwvh?

Update @ckeditor/ckeditor5-real-time-collaboration to 44.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j3mm-wmfm-mwvh is resolved across your whole dependency graph.

How do I detect GHSA-j3mm-wmfm-mwvh in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @ckeditor/ckeditor5-real-time-collaboration. 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.

How do I mitigate GHSA-j3mm-wmfm-mwvh if there is no patch (or I can't update yet)?

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 does O3 Security protect against GHSA-j3mm-wmfm-mwvh?

O3 pinpoints whether GHSA-j3mm-wmfm-mwvh is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-j3mm-wmfm-mwvh actively exploited in the wild?

No public exploit code has been indexed for GHSA-j3mm-wmfm-mwvh yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-j3mm-wmfm-mwvh?

GHSA-j3mm-wmfm-mwvh has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 42th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-j3mm-wmfm-mwvh?

GHSA-j3mm-wmfm-mwvh is classified as Cross-site Scripting (XSS) (CWE-79), CWE-80 (CWE-80). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-j3mm-wmfm-mwvh published, and has it been updated?

GHSA-j3mm-wmfm-mwvh was published on February 20, 2025 and was last updated on February 20, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

GHSA-j3mm-wmfm-mwvh

Cross-site scripting (XSS) in the CKEditor 5 real-time collaboration package

Also known asCVE-2025-25299

Published

Feb 20, 2025

Updated

Feb 20, 2025

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk42th percentile+0.21%

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

2 pkgs affected

📦@ckeditor/ckeditor5-real-time-collaboration📦ckeditor5-premium-features

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

Impact

During a recent internal audit, we identified a Cross-Site Scripting (XSS) vulnerability in the CKEditor 5 real-time collaboration package. This vulnerability can lead to unauthorized JavaScript code execution and affects user markers, which represent users' positions within the document.

This vulnerability affects only installations with Real-time collaborative editing enabled.

Patches

The problem has been recognized and patched. The fix will be available in version 44.2.1 (and above).

For more information

Email us at [email protected] if you have any questions or comments about this advisory.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@ckeditor/ckeditor5-real-time-collaboration`	≥ 41.3.0&&< 44.2.1	44.2.1
📦npm	`ckeditor5-premium-features`	≥ 42.0.0&&< 44.2.1	44.2.1

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @ckeditor/ckeditor5-real-time-collaboration. 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 @ckeditor/ckeditor5-real-time-collaboration to 44.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j3mm-wmfm-mwvh 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-j3mm-wmfm-mwvh 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-j3mm-wmfm-mwvh. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact During a recent internal audit, we identified a Cross-Site Scripting (XSS) vulnerability in the CKEditor 5 real-time collaboration package. This vulnerability can lead to unauthorized JavaScript code execution and affects user markers, which represent users' positions within the document. This vulnerability affects only installations with [Real-time collaborative editing](https://ckeditor.com/docs/ckeditor5/latest/features/collaboration/real-time-collaboration/real-time-collaboration.html) enabled. ### Patches The problem has been recognized and patched. The fix will be available

O3 Security · Impact-Aware SCA

Is GHSA-j3mm-wmfm-mwvh in your dependencies?

O3 detects GHSA-j3mm-wmfm-mwvh across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works