If your implementation uses server-to-server communication with either Secure Acceptance or Flex endpoints in the CAS/Test or Production environments  (listed below), you must install/import the associated Cloudflare SSL certificate from the zip file attached to this article.

Cybersource Endpoints:

CAS/TEST:

testflex.cybersource.com
testsecureacceptance.cybersource.com

Production:

flex.cybersource.com
secureacceptance.cybersource.com
flex.in.cybersource.com
secureacceptance.in.cybersource.com

Additional Information 

Infrastructure Enhancement, PCN and Cloudflare Sureroute Access