Release Notes for OpenCms 21

April 14, 2026: OpenCms 21 adds AI/LLM-based translation directly to the XML content editor and includes translation workflows for OpenAI and DeepL APIs. It also improves the upload dialog by allowing properties to be edited for multiple files at once. In addition, it adds a configurable secret provider for securely storing encrypted passwords or API keys in a protected file on the server. OpenCms 21 now supports Java 25 and requires at least Java 21 to run.

Main new features of OpenCms 21

• AI-Powered translations in the OpenCms XML content editor
  • Creating and maintaining multilingual content becomes significantly easier with the latest AI-driven translation capabilities in OpenCms.
• Secure sensitive data with the OpenCms Secret Provider
  • Sensitive configuration data can now be stored securely using the configurable Secret Provider in OpenCms, with AES encryption for enhanced protection.
• Supports Java versions 21 and 25
  • OpenCms stays up to date with modern Java versions and aligns with current platform requirements. It now supports Java 25 and the minimum required Java version has been raised to Java 21.
• Set properties for multiple images at once during upload
  • When uploading images, properties previously had to be assigned individually for each image. It is now possible to set a specified property for all uploaded images.
• Improvements in the "Optimize gallery" dialog
  • The “Optimize gallery” dialog now features new sorting options by file size. In addition, unused images can be deleted more quickly.
• Hiding the “Detail Pages” tab in the sitemap editor
  • In the sitemap editor, the “Detail Pages” tab in the dialog for adding pages can be hidden for users depending on their roles.

Further improvements in OpenCms 21

• Page editor: Allow copying write-protected elements.
• Workplace: Added users’ full names to the principal selection dialog.
• Workplace: Improved the “Edit new module” dialog.
• Workplace: Improved folder size formatting in the resource info dialog.
• Workplace: Confirm file selection filter with Enter key.
• Gradle build: Updated configuration for Gradle 8.10.
• Gradle build: Improved handling of module JARs.
• Solr: added update option for searchcontent in XSD searchsettings.
• Solr: Improved module import performance for external servers.
• Solr: Improved indexing performance for resources with relations.
• Solr: Updated Solr to version 10.
• Added test case for improved handling of missing XSDs.
• Cleaned up redundant legacy javax.* and jakarta.* API JARs in WEB-INF/lib.
• Pull request #825 file sorting by name in explorer table and tree (partial merge) (github pull request #825).
• Pull request #827 removes mavenLocal for more stable Gradle dependency resolution (github pull request #827).
• Pull request #831 modernizes Gradle plugin usage and build directory handling (github pull request #831).
• Pull request #832 updates Gradle to use lazy task registration (github pull request #832).
• Pull request #833 standardizes test execution for Gradle and IDE integration (github pull request #833).
• Pull request #837 Added .csv and .ai file type mappings to VFS resource types (github pull request #837).

Bug fixes in OpenCms 21

• Security: Fixed RCE vulnerability related to UGC.
• Security: Fixed CVEs by upgrading Apache Tika.
• Security: Fixed XXE issue for old import versions.
• Fixed flex cache issue with wrong entry after direct page open following publish.
• Fixed wrong accordion heading in the container page “Info” dialog.
• Fixed inactive save buttons in the i18n bundle editor.
• Fixed Solr highlighter configuration to use hl.method.
• Fixed dummy elements displayed on default detail pages.
• Fixed missing input validation in the resource type app.
• Fixed edge case issue when moving a user between OUs.
• Fixed upgrade wizard including demo template JARs.
• Fixed exception for unreadable content folders in resource type config.
• Fixed websites app error when server URL has no protocol.
• Fixed websites app removing a site on empty or invalid input.
• Fixed issue with reloaded element HTML sanitation breaking inline editing.
• Fixed issue #836 edit button shown for non-editable resources in the publish dialog (github issue #836).
• Fixed issue #838 undelete for Element Authors without the Editor role (github issue #838).

General OpenCms features

• The page editor allows WYSIWYG inline editing of web pages and arrangement of content by drag & drop.
• The form based editor allows editing of structured content in a well defined form mask.
• The sitemap editor allows to create new pages and re-arrange the navigation tree by drag & drop.
• Responsive "Mercury" default template based on Bootstrap 4 with many features.
• Headless API for accessing content as JSON from external applications.
• Content creation for mobile devices with preview and device specific content control.
• Structured contents can be defined using a simple XML schema.
• Easy to use "Online / Offline" workflow, changes must be approved before they become visible.
• Link management for all internal resources with broken link detection.
• Integrated image scaling and cropping.
• SEO features with automatic sitemap.xml generation and page alias support.
• Full featured user management that supports the concept of "Organizational Units" (OUs).
• Allows management of multiple websites within one installation.
• Contents can be served dynamically or exported to static HTML files.
• File access to the OpenCms content repository over a shared network / SMB drive.
• CMIS and WebDAV access to the OpenCms content repository.
• Integrates Apache SOLR for powerful content searching and noSQL like queries.
• Full text search for web pages as well as in office documents like PDF, MS Office and Open Office.
• Extensions can be added through a flexible module system.
• The "time warp" feature allows to view resources which are expired or not yet released.
• JSP integration for dynamic functionality in templates, dynamic forms etc.
• ... and many more

Backward compatibility

OpenCms 21 is backwards compatible with all OpenCms versions from 10 to 20. Templates and other OpenCms developed code from these versions should mostly work “out of the box” with version 21.

Note for Alkacon OCEE users: Alkacon OCEE users will need a new OCEE version for OpenCms 21. The update is free for Alkacon customers with a current OCEE subscription. Please contact Alkacon to obtain the new version.

Compatibility with Java versions, servlet containers and databases

OpenCms 21 is compatible with Java 25 and 21.

OpenCms 21 requires a Java Servlet 4.0 compliant web container. We have tested this release with Jetty and Tomcat. It works “out of the box” with Jetty 12 or Tomcat 9. Others have reported successful deployments of OpenCms on other web servlet containers like WildFly, GlassFish, WebLogic, WebSphere and Resin.

On the database side, we provide support for MySQL, MariaDB, Oracle, PostgreSQL, MS SQL Server, DB2 and HSQLDB.