Which firmware to download for Netscaler update

I need to upgrade netscaler firmware to address CVE-2019-19781.
Citrix have following 2 links for firmware download:-
https://www.citrix.com/downloads/citrix-adc/
https://www.citrix.com/downloads/citrix-gateway/
Which link should I use to download the package?
These are virtual appliance on ESXi.

1. One Netscaler current firmware is NS10.5: Build 55.8007.e.nc.
It has following features enabled:-        
 Feature                        Acronym              Status
-------                        -------              ------
 Load Balancing                 LB                   ON
 Content Switching              CS                   ON
 SSL Offloading                 SSL                  ON
 Rewrite                        REWRITE              ON
 Responder                      RESPONDER            ON
 AppFlow                        AppFlow              ON
Shoudl I download the "Netscaler Gateway 10.5.e" frimware for it from the https://www.citrix.com/downloads/citrix-gateway/ URL?
If I choose this one then the latest one is from Sep 25, 2017 which won't cover this CVE.

If I choose the "Netscaler Gateway 10.5" frimware then the latest is Jan 24, 2020 which shoudl cover this CVE.

If I choose the "Netscaler ADC release 10.5" frimware/virtual appliance for it from the https://www.citrix.com/downloads/citrix-adc/ URL then the latest is from Jan 24, 2020 which should cover this CVE.
Which one shoudl I choose?

2. Another netscaler has firmware - NS12.1: Build 50.31.nc
It has following features enabled:-
 Feature                        Acronym              Status
-------                        -------              ------
Load Balancing                 LB                   ON
Content Switching              CS                   ON
SSL Offloading                 SSL                  ON
SSL VPN                        SSLVPN               ON
Responder                      RESPONDER            ON
AppFlow                        AppFlow              ON
CallHome                       CH                   ON

 Mode                           Acronym              Status
-------                        -------              ------
Fast Ramp                      FR                   ON
Edge configuration             Edge                 ON
Use Subnet IP                  USNIP                ON
Layer 3 mode (ip forwarding)   L3                   ON
Path MTU Discovery             PMTUD                ON
Shoudl I download the "Netscaler Gateway 12.1" frimware for it from the https://www.citrix.com/downloads/citrix-gateway/ URL?

OR 

"Netscaler ADC release 12.1" frimware/Virtual Appliance from https://www.citrix.com/downloads/citrix-adc/ URL