We decided to do another release of the 5.1 series to fix critical bugs to be included in an upcoming version of WildFly. This may be the last release of the 5.1 series, so we recommend that you migrate to 5.2 for future bugfixes.
Hibernate ORM 5.1.5.Final:
tag is here;
changes are listed here (or, for people without a Hibernate Jira account, here);
release bundles are at SourceForge and BinTray.
For information on consuming the release via your favorite dependency-management-capable build tool, see https://hibernate.org/orm/downloads/