September 1, 2023
Pantheon has pushed an update to WordPress and Drupal 7 core upstreams which sets PHP 8.1 as the new default PHP version, rather than 7.4.
Please test this core update thoroughly before deploying to the Live environment. If your site requires an older version of PHP, or if you'd like to upgrade to PHP 8.2, see Pantheon’s documentation on how to manage PHP versions via the pantheon.yml configuration file.