PostgreSQL is vulnerable to privilege escalation. An attacker with access to the postgres user account could use these flaws to obtain root access on the server machine.
www.securitytracker.com/id/1039983
access.redhat.com/errata/RHSA-2017:3402
access.redhat.com/errata/RHSA-2017:3403
access.redhat.com/errata/RHSA-2017:3404
access.redhat.com/errata/RHSA-2017:3405
access.redhat.com/security/cve/CVE-2017-15097
access.redhat.com/security/updates/classification/#moderate
bugzilla.redhat.com/show_bug.cgi?id=1508985
bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-15097