The maintenance of Hibernate projects focuses on the latest series. When a series reaches end-of-life, it is no longer maintained and thus will no longer receive fixes for bugs or even vulnerabilities.
Application developers temporarily unable to upgrade from end-of-life'd versions of Hibernate projects but still requiring fixes for security vulnerabilities should look for commercial, end-of-life support.
Commercial Offerings
Below are commercial offerings that the Hibernate team is familiar with, and which provide end-of-life support for Hibernate projects (among others).
Red Hat’s Jakarta EE application server based on WildFly.
The Extended Life Cycle Support subscription generally covers end-of-life’d versions of Hibernate projects.