Like GPU, CPUs is able to mine.
But It's very very low. I think you don't should try (It makes CPU always more than 90%, maybe 100%).
I have tried it. For my computer : CPU Intel Core i7 8700K 3.7Ghz Turbo Up to 4.7Ghz / 12MB / 6 Cores, 12 Threads / Socket 1151 v2 (Coffee Lake ).
after 6 hours and full power, just earn about 700 santoshi.