I am using debian version 8.9. I have received several "updates available" notices that include Berkeley database utilities that are described as "blocked". I just tried aptitude. It says that an upgrade of the package db5.1-util from version 5.1.29-5 to 5.1.29-9 is available, but that I (the user) have asked to stay the current version. I did not do this intentionally, and don't think I have ever used the programs in this package.