DRUPAL-CORE-2021-011
Quick fix
DRUPAL-CORE-2021-011 — drupal/core: upgrade to the fixed version with the command below.
composer require drupal/core:^8.9.20Details
The Drupal project uses the [CKEditor](https://github.com/ckeditor/ckeditor4) library for WYSIWYG editing. CKEditor has released [a security update that impacts Drupal](https://ckeditor.com/cke4/release/CKEditor-4.17.0), along with a [hotfix for that update](https://ckeditor.com/cke4/release/CKEditor-4.17.1).
Vulnerabilities are possible if Drupal is configured to allow use of the CKEditor library for WYSIWYG editing. An attacker that can create or edit content (even without access to CKEditor themselves) may be able to exploit one or more Cross-Site Scripting (XSS) vulnerabilities to target users with access to the WYSIWYG CKEditor, including site admins with privileged access.
For more information, see CKEditor's security advisories:
* [CVE-2021-41165: HTML comments vulnerability allowing to execute JavaScript code](https://github.com/ckeditor/ckeditor4/security/advisories/GHSA-7h26-63m7-qhf2) * [CVE-2021-41164: Advanced Content Filter (ACF) vulnerability allowing to execute JavaScript code using malformed HTML](https://github.com/ckeditor/ckeditor4/security/advisories/GHSA-pvmx-g8h5-cprj)
This advisory is not covered by [Drupal Steward](/steward).
Are you affected?
Enter the version of the package you're using.