This update for postgresql96 fixes the following issues:
CVE-2017-7547: Further restrict visibility of pg_user_mappings.umoptions, to protect passwords stored as user mapping options. (bsc#1051685) * CVE-2017-7546: Disallow empty passwords in all password-based authentication methods. (bsc#1051684) * CVE-2017-7548: lo_put() function ignores ACLs. (bsc#1053259)
The changelog for this release is here: https://www.postgresql.org/docs/9.6/static/release-9-6-4.html