No new features have been included in this maintenance release.
Project Import and Export
Some edge cases where not properly supported and have been fixed. This includes both project export / import when rehosting, and exporting / importing the index to be used when creating a comment or a finding within a review.
The list of known issues can be found on the known issues page.
There is no specific action to take upon migrating from version 3.x.x. Simply follow the Updating SECollab guidelines.