If there is no path to villagers, zombies go the closest they can and then just stand there doing nothing indefinitely unless damaged by a player.

I didn't think much of it, but the server admin complained about the server using 100% CPU. On killing the zombies that were trying to get into my iron golem farm building with villagers, the CPU usage returned to normal.

So basically, whenever zombies spawn and try to path to the village, the CPU will spike. I have ringed my building with fire as a stopgap measure, but I shouldn't have to be concerned about the server's CPU when making farms

This should be reproducable by making a minimal village and sticking some 20 villagers in a completely sealed space and waiting for interested zombies.