Pantheon release notes

As a follow-up to our release note announcing the removal of PHP Runtime Generation 1, we're now providing specific dates for the removal from the platform.

What's changing when?

All environments that have not been upgraded to PHP Runtime Generation 2 will be auto-upgraded on the following schedule:

• April 6, 2026: Dev and Multidev environments will be auto-upgraded to Generation 2
• April 13, 2026: Test and Live environments will be auto-upgraded to Generation 2

After these dates, PHP Runtime Generation 1 will no longer be available.

Action Required

We strongly recommend that all site owners proactively test and upgrade to Generation 2 rather than waiting for the auto-upgrade. This allows you to:

• Test your site in Dev and Multidev environments before the upgrade reaches Test and Live
• Address any compatibility issues on your own timeline
• Avoid potential downtime or unexpected issues during the auto-upgrade

Please review the Known Changes and Requirements if you are still in the process of upgrading your site.

The latest version of WordPress, 6.9.1, is available on Pantheon as of February 4, 2026.

Action required

Upgrade to WordPress 6.9.1 right from your Pantheon dashboard or Terminus to access the latest features, fixes, and security enhancements. See related documentation for how to apply core updates.

Highlights

• This minor release includes fixes for 49 bugs throughout Core and the Block Editor, addressing issues affecting multiple areas of WordPress including the block editor, mail, and classic themes. For a full list of bug fixes, please refer to the release candidate announcement.

WordPress 6.9.1 is a short-cycle maintenance release. The next major version of WordPress will be 7.0; it is scheduled for release on 9 April 2026 at WordCamp Asia.

For full details about WordPress 6.9.1, see the official release announcement.

Key Changes: CLI Rename

We've renamed the Content Publisher CLI from pcc to cpub to reflect our product naming. This change affects all CLI commands and the associated NPM package.

CLI Command

• Old: pcc
• New: cpub

NPM Package

• Old: @pantheon-systems/pcc-cli
• New: @pantheon-systems/cpub-cli

Action Required

Please update your existing commands by replacing pcc with cpub. All flags and arguments remain the same. Deprecated pcc CLI still functional with warning messages.

To update your installation:

1. First, log out of the old CLI:

2. Uninstall the old package:

3. Install the new package:

4. Login to the new CLI:

Additional Changes

• Connected Accounts are no longer tied to the user’s browser and has been migrated to server-side account management improving overall user experience
• Dashboard now displays user account subscription and usage allowing users to keep track of their account usage limits
• A search function has been added to the Collections dropdown in the Tokens modal for easier navigation in workspaces with many collections
• The App Router starter kit default installation no longer uses Static Site Generation (SSG)
• Minor bug fixes and UX improvements

Pantheon has released a new version of our WP SAML Auth WordPress plugin. This update focuses on modernizing PHP support and providing developers with more granular control over SAML configurations.

What's New

• PHP 8.4 Compatibility: Full support for PHP 8.4 has been added.
• Updated PHP Requirements: The minimum supported PHP version has been increased to 7.4 to ensure better security and performance.
• WordPress 6.9 Compatibility: Confirmed compatibility with WordPress 6.9.
• Enhanced Configuration: Added the wp_saml_auth_internal_config filter, allowing developers to customize the OneLogin SAML configuration.
• SimpleSAMLphp 2.x Support: Improved auto-detection for SimpleSAMLphp 2.x and optimized autoloader discovery to skip redundant processes when the SimpleSAML\Auth\Simple class is already loaded.

Bug Fixes

Settings Page Warnings: Fixed a warning message on the plugin's settings page that appeared for users not utilizing SimpleSAML.

Important: Compatibility & Testing

While this update improves autoloader discovery, it changes how the plugin interacts with the local environment. We strongly recommend testing in a lower environment before upgrading especially if you use:

• Non-Standard Installations: Custom SimpleSAMLphp installations located in non-standard directories.
• Manual Autoloaders: Custom autoloader code that manually handles the loading of SimpleSAMLphp.

Action required

We encourage you to upgrade to the latest version of WP SAML Auth as soon as possible to take advantage of the latest features and compatibility updates. updating to get the latest features and compatibility updates.

If you have questions or concerns, please open issues in the queue for the plugin.

Following the successful rollout of PHP Runtime Generation 2 for all environments that have not opted-out, we are now preparing to remove PHP Runtime Generation 1 from the platform starting April 6, 2026.

What's changing when?

Between April 6 and April 17, 2026, all environments that have not been upgraded will be auto-upgraded to Generation 2. Opting out will no longer be available.

Action Required

Please view the Known Changes and Requirements list if you are still in the process of upgrading your site. We recommend all site owners proactively test and upgrade to Generation 2 rather than waiting for this auto-upgrade.

We are removing ionCube support from the platform on March 8, 2026. This PHP extension was prevously only available for PHP 8.1 on PHP Runtime Generation 1.

Pantheon continually reviews our PHP runtime and explores opportunities to optimize performance and build times.

If your application uses ionCube, please contact support or your Customer Success Manager to explore options for your use case.

The latest version of WordPress, 6.9, is available on Pantheon as of December 02, 2025.

Action required

Upgrade to WordPress 6.9 right from your Pantheon dashboard or Terminus to access the latest features, fixes, and security enhancements. See related documentation for how to apply core updates.

For full details about WordPress 6.9, see the release notes

Pantheon is updating its platform to align with current IANA standards by removing support for deprecated MIME types that use the x- prefix. This change will be introduced on November 17, 2025.

The following deprecated types have been updated to their modern, IANA-standard equivalents. No action is required for these files unless you have custom code explicitly referencing the old format.

• application/mathml+xml mml
• application/javascript js mjs
• image/vnd.microsoft.icon ico
• image/bmp bmp
• application/vnd.rar rar
• audio/mp4 m4a
• video/mp4 m4v
• font/ttf ttf
• text/vcard vcf
• application/vnd.amazon.mobi8-ebook mobi

The following deprecated x- prefixed MIME types will be removed entirely from platform support:

• text/x-component htc
• image/x-jng jng
• application/x-7z-compressed 7z
• application/x-cocoa cco
• application/x-javascript
• application/x-java-archive-diff jardiff
• application/x-java-jnlp-file jnlp
• application/x-makeself run
• application/x-perl pl pm
• application/x-pilot prc pdb
• application/x-redhat-package-manager rpm
• application/x-sea sea
• application/x-shockwave-flash swf
• application/x-stuffit sit
• application/x-tcl tcl tk
• audio/x-realaudio ra
• video/x-flv flv
• video/x-mng mng
• video/x-ms-asf asx asf
• video/x-ms-wmv wmv
• video/x-msvideo avi
• application/x-plist plist

Action Required

Review any custom code or configurations that utilize the removed MIME types and update them to use their respective IANA-standard equivalents.

If you encounter a file type that IANA does not yet handle, or if you require an alternative configuration, please follow the instructions in our documentation.