Compatibility summary
You will need a travel adapter in Cuba; plug types used there differ from Brazil.
Plug comparison
Brazil plug types: C N
Cuba plug types: A B
There is no common plug type between Brazil (C N) and Cuba (A B). You need a travel adapter.
Voltage comparison
Brazil: 127V, 60Hz
Cuba: 120V, 60Hz
Voltage difference is within a range many devices tolerate; check your appliance label.