On 26 October 2017, VMware released VMware vCenter Server 6.5 Update 1b. In this article I will show you how to easily update vCenter Server Appliance (VCSA) from version 6.5.x to the latest 6.5 Update 1b using vCenter Server Appliance Management Interface (VAMI). This version is also identified by version number 6.5.01100 and build number 6816762 (you can check KB2143838 for all vCenter build and version numbers – unfortunately VMware is a little behind to update this KB article).
Note: If you look for VCSA installation instructions, check this article: How to Install VCSA 6.5 (VMware vCenter Server Appliance).
In my case, I will update vCenter Server Appliance from 22.214.171.12400 build 5318154 to the latest 126.96.36.19900 build 6816762. I will start by accessing VAMI, on port 5480 of the vCenter Server (https://vcenter.lab.local:5480/ for my lab). I will authenticate with root user and corresponding password.