Varbase follows the Drupal 8/9 release cycle. Therefore, a version of Varbase is named 9.0.x uses the same major version of Drupal 9.4.x.
Varbase Supported Versions
Varbase supports one major version. That is the most recent one using the most recent Drupal 8/9 major version (e.g. 8.9.x , 9.2.x).
Once the most recent stable version of Drupal 9 is released (e.g. 9.4.x), Varbase will release its 9.0.x version and drop support of the oldest supported version (e.g. 8.8.x).
Upgrade paths will always be provided to guarantee a smooth move between Varbase versions.
See the below image for an illustration of supported versions and major release cycle: