Cybersecurity
If you were handed 3 USB drives, one with source data, a second with a program, and a third to hold the results... could you run the program to process the data, and save it with no risk to the computer you used?
First- no such thing as “no risk”.
The USB separation doesn’t matter. Once loaded into memory and running you have many ways in which a dangerous program can interact with the machine. The general way to handle this type of need is to use an ephemeral virtual machine so you can just nuke it at the end. Otherwise, plan to reimage your computer.
You could unplug the hard drive and complete the operation using a Linux live USB or cd.
Even then you are probably at risk of exceedingly clever exploits that can live in the bios.
I would say that generally the answer is no. If you plug a physical device into your computer you should assume that it's at least possible it can do things you would not like very much.
I could not vouch for the computer and it's USB stack, so no, but in practice I would use a sandboxed runtime for the program, a virtual machine for example. I would also air gap the computer.
“Cybersecurity” is what you call computer security if you don’t know what you’re talking about