This release closes security hole CVE-2016-2193, where a query plan might get reused for more than one ROLE in the same session. This could cause the wrong set of Row Level Security (RLS) policies to be used for the query.
The update also fixes CVE-2016-3065, a server crash bug triggered by using pageinspect with BRIN index pages. Since an attacker might be able to expose a few bytes of server memory, this crash is being treated as a security issue.
This release adds many new features which enhance PostgreSQL's flexibility, scalability and performance for many different types of database users, including improvements to JSON support, replication and index performance.