We have an authentic version of the Rigveda: written carefully and supported by the systematic, uninterrupted oral tradition of Vedic Chanting. Due to the oral tradition, the Rigveda is free from corruption completely.
The oral tradition is authentic and reliable. You can see this from the fact that there are no / very minor differences between the printed critical edition of the Rigveda and the oral tradition.
“The Adiparvan in Dr Suktankar's critical edition of the Mahabharata is now complete and I have no hesitation in saying this is the most important event in the history of Sanskrit philology since Max Muller’s edition of the Rigveda with Sayana’s commentary” ~ Prof Winternitz.