Drupal security updates, week of 15 April 2026: Drupal core

Week of 15 April 2026

Drupal publishes security updates on Wednesdays. This week there was one, for Drupal core itself. Between them they carry 3 security fixes, because a module can fix several bugs in one update: Drupal core fixed 3.

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

Critical · Drupal core · every Drupal site · 3 security fixes

This is the main software that runs the website.

3 security fixes in one update. Drupal core fixed 3 separate security bugs this week: 2 cross site scripting, 1 gadget chain. One update covers all of them. The most serious, SA-CORE-2026-001, is explained here and the full list is at the end of the card.

A visitor without an account could cause unsafe code to run in message boxes on the site. This could allow them to see or change some information but they could not take over the whole site.

Who could do thisAnyone visiting the site. No login needed.
Does it apply to youEvery Drupal site on an affected version.
Has it been used in attacksNo sign of it.
How urgentDrupal rates this critical. Cyber Essentials expects a fix within 14 days. Do it this week.

Tell your developerUpdate Drupal core to 11.3.7, 11.2.11, 10.6.7 or 10.5.9, whichever branch you are on.

For developers: what the fix changed

This release carries 3 security fixes. The summary below is for SA-CORE-2026-001, the most serious of them.

The fix sanitises button attributes for AJAX modal dialog boxes by applying Xss::filter to string values in the render method of core/lib/Drupal/Core/Ajax/OpenDialogCommand.php.

Also in this release The release also fixes two other security advisories and updates Composer to version 2.9.7.

11.3.6 to 11.3.7 5 commits, 8 files.

composer.lock +11 −11
composer/Metapackage/CoreRecommended/composer.json +1 −1
composer/Metapackage/PinnedDevDependencies/composer.json +2 −2
core/lib/Drupal.php +1 −1
core/lib/Drupal/Core/Ajax/OpenDialogCommand.php +15 −0 fix
core/lib/Drupal/Core/Template/Attribute.php +3 −0
core/modules/ckeditor5/src/Controller/EntityLinkSuggestionsController.php +1 −1
core/modules/views/src/ViewExecutable.php +27 −0

Full diff, 11.3.6 to 11.3.7 · Full diff, 11.2.10 to 11.2.11 · Full diff, 10.6.6 to 10.6.7 · Full diff, 10.5.8 to 10.5.9

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

All 3 security bugs this update fixes, worst first. Each link is the drupal.org notice for that one.

Critical · Cross site scripting · SA-CORE-2026-001
Moderately critical · Cross site scripting · SA-CORE-2026-003
Moderately critical · Gadget Chain · SA-CORE-2026-002

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 15 April 2026

Critical: 1 update

Drupal core

Send me your Drupal site's address.

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Reference