Thank you all.
In my simulation diodes work just fine. This is only the input of a bit more complicated circuit, so I will get back to you if I face some problems because of this. That is why I will mark this as solved.
As far as output load is concerned, there will be another level of MOSFETs and then the CAN bus. The device that I am working with for some reason needs 7V and 12V pulse to start, and afterwards it communicates using good old CAN. So, this input circuit is only a voltage level selector for a CAN controller.
Thank you.