Upgrading vCMP guest

I believe the following is what you're looking for.

Update or upgrade BIG-IP VIPRION systems (vCMP) | BIG-IP update and upgrade guide

i am adding the steps those i have in my SOPs

Upgrade vCMP Guest Using Host-Imported ISO

Pre-Checks (Very Important)

Before starting:

Confirm ISO is uploaded on vCMP Host

Check available disk space on Guest

Take UCS backup

Confirm HA status (if guest is in cluster)

Plan maintenance window (traffic impact depends on HA setup)

Step 1: Verify ISO on vCMP Host

On the vCMP Host GUI:

System → Software Management → Image List

Confirm your BIG-IP ISO (e.g., BIGIP-17.1.x.iso) is present.

If not, upload it:

System → Software Management → Image List → Import

Step 2: Install Image on the vCMP Guest

Important: You DO NOT install it from the host into the guest automatically.

The ISO must be made available to the guest.

Option A (Recommended – GUI Method)

Login to the vCMP Guest GUI

Navigate to:

System → Software Management → Image List

You should see the image (shared from host)

Click Install

Choose a new boot location (e.g., HD1.2)

install

I think there was some bug about upgrading quests from the host CLI/GUI/API but even if you upgrade the quests from inside it is not a big issue as the vCMP host after couple of minutes detects the change as seen in "vcmp quest status" , so just take new ucs file from the host after upgrade and this is something that F5os velos/rseries for example does not unfortunately as there you can't also upgrade from the host and the host does not detect the change, so if there is RMA it is a big issue.