How to update Acrobat X to secure Flexnet Publisher

[joinott]

Secunia PSI is telling me that Flexnet Publisher is insecure:
https://www.cvedetails.com/cve/CVE-2015-8277/‌  - this is a very serious vulnerability
This came with Acrobat X

Acrobat X tells me I have its latest version when I "Check for Updates"

Flexera won't support end-users - says the license manager must be obtained from the software vendor.

What do I do ?