PostgreSQL is vulnerable to authorization bypass. It is because it did not properly check the return values of certain standard library functions. If the system is in a state that would cause the standard library functions to fail, for example memory exhaustion, an authenticated user could exploit this flaw to disclose partial memory contents or cause the GSSAPI authentication to use an incorrect keytab file.
ubuntu.com/usn/usn-2621-1
www.debian.org/security/2015/dsa-3269
www.debian.org/security/2015/dsa-3270
www.postgresql.org/about/news/1587/
www.postgresql.org/docs/9.0/static/release-9-0-20.html
www.postgresql.org/docs/9.1/static/release-9-1-16.html
www.postgresql.org/docs/9.2/static/release-9-2-11.html
www.postgresql.org/docs/9.3/static/release-9-3-7.html
www.postgresql.org/docs/9.4/static/release-9-4-2.html
access.redhat.com/security/updates/classification/#moderate
rhn.redhat.com/errata/RHSA-2015-1194.html