Would it be possible for you to back port these changes to 5.2.8.Final?

Do you mean release a version 5.2.8-2 for Hibernate ORM with a fix for this specific issue? That's very unlikely to happen. We only have three levels in our versioning scheme, though some vendors such as Red Hat may add a level of their own to backport fixes for their customers.

I don't see the point though: if you are willing to upgrade to a (hypothetical) 5.2.8-2, could you not just upgrade to 5.2.12.Final or later?