The release notes are available here: https://docs.apigee.com/release/notes/20121700-apigee-developer-services-portal-release-notes

For Apigee Cloud customers -
Cloud customers hosted on Pantheon should apply updates to their site using the Pantheon dashboard:
http://apigee.com/docs/developer-services/content/working-pantheon#maintainyoursite-applyanapigeeupdatetothedeveloperservicesportal

and make sure all environments have been patched using the standard workflow:
http://helpdesk.getpantheon.com/customer/portal/articles/383609-using-the-pantheon-workflow

For Apigee Private Cloud customers -
Apigee Private Cloud customers should make sure their systems are following Drupal security advisories: https://www.drupal.org/security

Follow the following process to update Drupal core and contributed modules: https://docs.apigee.com/private-cloud/v4.50.00/portal-upgrading-drupal

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