Apache Calcite Avatica 1.21.0 is a maintenance release with dependency upgrades and added support for Oracle JDK 16 to 18. Of particular note is Log4j2 being upgrade to 2.16.0 and subsequently 2.17.0 and 2.17.1 to address CVE-2021-44228, CVE-2021-45105 and CVE-2021-44832. See the list of [bug fixes and new features]({{ site.baseurl }}/docs/history.html#v1-21-0) for more information.