Drupal security updates, week of 16 September 2026: Drupal core

Week of 16 September 2026

Drupal publishes security updates on Wednesdays. This week there was one, for Drupal core itself.

One is for Drupal core. That applies to every Drupal site, so start there.

Each card says what the module does, what went wrong, who could do it, whether it applies to you, how urgent it is, and the one line to send to your developer. Worst rated first, and most used first within a rating.

New here? How Drupal security updates work explains who publishes these, why they matter and what the ratings mean. Earlier weeks and a search by module are on the main page.

Drupal core

Moderately critical · Drupal core · every Drupal site · SA-CORE-2026-013 · on drupal.org

This is the main software that runs the website and lets people manage its content.

A person with an ordinary account who can create or edit content could hide harmful code on the site. If a site administrator or another user with access to the visual text editor views that content, the code could run and let the attacker view private information or change content. The attacker could not do this without someone else viewing the content first.

Who could do thisOnly someone with a login on your site.
Does it apply to youThis applies if the site is set up to use the CKEditor visual text editor.
Has it been used in attacksNo sign of it.
How urgentDrupal rates this moderately critical. Include it in your next routine update, within the month.

Tell your developerUpdate Drupal core to 11.4.7, 11.3.17 or 10.6.17, whichever branch you are on.

For developers: what the fix changed

The provided diff consists of minified CKEditor 5 build files, making it impossible to confidently isolate the specific changes that fix the XSS vulnerability in the engine package.

The fix is not clearly separable from the other changes in this release, so treat the summary above as a pointer rather than a finding.

Also in this release The release updates the CKEditor 5 library to a new version, resulting in widespread minification and module ID changes across the compiled assets.

11.4.6 to 11.4.7 2 commits, 44 files including 1 test.

composer.lock +5 −5
composer/Metapackage/CoreRecommended/composer.json +2 −2
composer/Metapackage/DevDependencies/composer.json +1 −1
composer/Metapackage/PinnedDevDependencies/composer.json +2 −2
core/assets/vendor/ckeditor5/autosave/autosave.js +1 −1 fix
core/assets/vendor/ckeditor5/basic-styles/basic-styles.js +0 −0
core/assets/vendor/ckeditor5/block-quote/block-quote.js +1 −1 fix
core/assets/vendor/ckeditor5/bookmark/bookmark.js +0 −0
core/assets/vendor/ckeditor5/ckbox/ckbox.js +0 −0
core/assets/vendor/ckeditor5/ckeditor5-dll/ckeditor5-dll.js +0 −0
core/assets/vendor/ckeditor5/code-block/code-block.js +0 −0
core/assets/vendor/ckeditor5/editor-balloon/editor-balloon.js +1 −1 fix

Full diff, 11.4.6 to 11.4.7 · Full diff, 11.3.16 to 11.3.17 · Full diff, 10.6.16 to 10.6.17

The comparison is against the release immediately before the fix. If your site is on an older release, more will have changed.

Send me your Drupal site's address.

I'll tell you what I can see from outside, what the Drupal 10 end of life on 9 December means for it, and what it would cost to have me keep it patched. There's no charge for that and no obligation. peter@peterbrady.co.uk

Compiled 10 October 2026 as part of the archive back to January 2026, from the advisories published by the Drupal security team on drupal.org. The facts on each card are theirs. The plain English is mine, with help from a language model. In the archive the cards rated critical or above were read before publishing and the rest were checked by sampling. Install counts are today's, not the count on the day of the advisory.

Get in touch

Tell me who you are, what your organisation does, and what you need. That might be a Drupal site that needs looking after, an upgrade to get done before December, or an agency that needs Drupal cover.

If I can help, I'll say so and suggest a call. If I can't, I'll tell you straight away rather than waste your time.

For context: I work mainly with UK charities, membership bodies and research organisations, and with the agencies that look after their websites. Not recruiters.

Or start smaller and connect with me on LinkedIn. That's where I post what I find digging around in charity and grants data, and where the free tools turn up first.

Week of 16 September 2026

Moderately critical: 1 update

Drupal core

Send me your Drupal site's address.

Get in touch

Links

Reference