I suggest following https://wiki.ubuntu.com/StableReleaseUpdates#New_upstream_microreleases, assuming the changes to 4.0.4 all qualify, to bring Xenial and Zesty both up to 4.0.4.
I suggest following https:/ /wiki.ubuntu. com/StableRelea seUpdates# New_upstream_ microreleases, assuming the changes to 4.0.4 all qualify, to bring Xenial and Zesty both up to 4.0.4.