I have a security system in my home and 3 more cameras that I need to add to my garage. There are 2 Ethernet cables running to my garage ( one cat 5e and one cat 8)

As of now the cat 8 is connected to my router/ signal repeater in the garage, and the cat 5e is connected to my 3d printer from my PC via a USB converter.

What I need is a solution to connect my 3 Power over Ethernet cameras in my garage to my NVR inside my home. I would really like to avoid having to run 3 more Ethernet cables so I am here looking for advice.