We have raised a request earlier to certify PostgreSQL 9.5 version for CA SiteMinder Policy Server 12.7. This is required due to mandatory AWS upgrade of PostgreSQL.
Release : 12.7
Component : SITEMINDER -POLICY SERVER
Please note that Siteminder 12.7 reaches End Of Service (EOS) on October 31, 2020:
Certifying a database would take 2 months minimum, so August would be a reasonable time frame. In this case PostgreSQL 9.5 would be supported for 2 months until you had to upgrade siteminder.
In otherwords, product management have stated in at least one previous case recently that they are not going to certify PostgreSQL 9.5 with Siteminder 12.7.
You can run with PostgreSQL 9.5 under the "6.4 Reasonable Commercial Effort Statement" in our platform matrix:
Please note that Siteminder 12.8 support PostgreSQL 9.6, see page 7:
In summary, considering Siteminder 12.7 is reaching EOS in 5 months, you would be better served by upgrading siteminder. You are somewhat supported usign PostgreSQL 9.5 by the "Reasonable Commercial Effort Statement".