In DSpace-CRIS we working to upgrade Spring version from the current version used by DSpace. We noticed that from the next major release 5.x Spring removed the support for Hibernate 4 that DSpace use behind the scene (the version of Hibernate declared is the 5.2.8.Final). In DSpace-CRIS using the transaction abstraction managed by Spring we have encountered some deprecated or missing code, and should be a good idea if also DSpace jumping on the new Spring version (from 4.3.6.RELEASE to the 5.0.2.RELEASE - release at November 2017 and at moment the last version of Spring on Maven central). It is an unecessary task but usefull to go in advance and build the DSpace 7.x release with the last version of the most critical component that it uses.
We will provide a Pull Request asap.