Kamailio SIP Server v4.0.6stable is out – a minor release including fixes in code and documentation since v4.0.0 – configuration file and database compatibility is preserved.
Kamailio (former OpenSER) v4.0.6 is based on the latest version of GIT branch 4.0, therefore those running previous 4.0.x versions are advised to upgrade. There is no change that has to be done to configuration file or database structure comparing with older v4.0.x.
Extra note to inform that in order to get 3.3.x packages hosted by the new APT repository, version 3.3.7 was released from branch 3.3. That should allow exiting deployments on 3.3.x to use the new repository and migrate easier to newer Kamailio releases. Beware that 3.3 is no longer officially maintained as stable branch, thus is recommended you upgrade to 4.0.x, or even better, 4.1.x.