It probably won't break the microcontroller permanently.
But one thing to be aware of, if this will ever happen outside of 'startup' then it can swamp the ADC. The issue is, the ADC is only rated as producing accurate results from 0-Vdd for instance. It won't be damaged if you go out of that range, but it also might not clip correctly. In fact, it might even cause adjacent channels to misbehave (I have encountered this behaviour on both PIC32 and TI's TM4C series) which can be a really difficult bug to solve.