How severe is GHSA-m8fw-p3cr-6jqc?

GHSA-m8fw-p3cr-6jqc has a CVSS score of 4.7/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-m8fw-p3cr-6jqc?

GHSA-m8fw-p3cr-6jqc affects the following packages: typo3/cms-rte-ckeditor (Packagist), typo3/cms-rte-ckeditor (Packagist), typo3/cms-rte-ckeditor (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-m8fw-p3cr-6jqc?

Update typo3/cms-rte-ckeditor to 9.5.42 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m8fw-p3cr-6jqc is resolved across your whole dependency graph.

How do I detect GHSA-m8fw-p3cr-6jqc in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3/cms-rte-ckeditor, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-m8fw-p3cr-6jqc if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is GHSA-m8fw-p3cr-6jqc actively exploited in the wild?

No public exploit code has been indexed for GHSA-m8fw-p3cr-6jqc 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.

When was GHSA-m8fw-p3cr-6jqc published, and has it been updated?

GHSA-m8fw-p3cr-6jqc was published on July 25, 2023 and was last updated on February 4, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘

🐘 Packagist

Not in CISA KEV

MEDIUM severity

Cross-Site Scripting in CKEditor4 WordCount PluginGHSA-m8fw-p3cr-6jqc

MEDIUM

GHSA-m8fw-p3cr-6jqc is a medium-severity (CVSS 4.7) vulnerability in typo3/cms-rte-ckeditor. A fix is available for typo3/cms-rte-ckeditor — see the affected versions and patch details below.

Published

Jul 25, 2023

Updated

Feb 4, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Feb 4, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

3 pkgs affected

🐘typo3/cms-rte-ckeditor🐘typo3/cms-rte-ckeditor🐘typo3/cms-rte-ckeditor

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

Description

CVSS: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C (4.4)

Problem

The WordCount plugin (npm:ckeditor-wordcount-plugin) for CKEditor4 is vulnerable to cross-site scripting when switching to the source code mode. This plugin is enabled via the Full.yaml configuration present, but is not active in the default configuration.

In default scenarios, exploiting this vulnerability requires a valid backend user account. However, if custom plugins are used on the website frontend, which accept and reflect rich-text content submitted by users, no authentication is required.

Solution

Update to TYPO3 versions 9.5.42 ELTS, 10.4.39 ELTS, 11.5.30 that fix the problem described above.

Credits

Thanks to Sybille Peters who reported this issue, and to TYPO3 core & security team member Oliver Hader who fixed the issue.

References

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`typo3/cms-rte-ckeditor`	≥ 9.5.0&&< 9.5.42	9.5.42`composer require typo3/cms-rte-ckeditor:^9.5.42`
🐘Packagist	`typo3/cms-rte-ckeditor`	≥ 10.0.0&&< 10.4.39	10.4.39`composer require typo3/cms-rte-ckeditor:^10.4.39`
🐘Packagist	`typo3/cms-rte-ckeditor`	≥ 11.0.0&&< 11.5.30	11.5.30`composer require typo3/cms-rte-ckeditor:^11.5.30`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3/cms-rte-ckeditor, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update typo3/cms-rte-ckeditor to 9.5.42 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m8fw-p3cr-6jqc is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

> ### CVSS: `CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C` (4.4) ### Problem The [WordCount](https://ckeditor.com/cke4/addon/wordcount) plugin ([`npm:ckeditor-wordcount-plugin`](https://www.npmjs.com/package/ckeditor-wordcount-plugin)) for CKEditor4 is vulnerable to cross-site scripting when switching to the source code mode. This plugin is enabled via the `Full.yaml` configuration present, but is not active in the default configuration. In default scenarios, exploiting this vulnerability requires a valid backend user account. However, if custom plugins are used on the website

O3 Security · Impact-Aware SCA

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