"This release closes security hole CVE-2016-0773, an issue with regular expression (regex) parsing. Prior code allowed users to pass in expressions which included out-of-range Unicode characters, triggering a backend crash. This issue is critical for PostgreSQL systems with untrusted users or which generate regexes based on user input.
The update also fixes CVE-2016-0766, a privilege escalation issue for users of PL/Java. Certain custom configuration settings (GUCS) for PL/Java will now be modifiable only by the database superuser."
More info: http://www.postgresql.org/about/news/1644/