When backing into my driveway the brakes failed. I was nosing the car across the street towards the neighbors driveway so I could put the car in reverse and back it into the driveway. I applied the brakes while traveling at about 3-4mph when the brakes had little resistance and went straight to the floor and the vehicle continued moving forward. Attempted to apply brakes again and the same result. Ended up hitting the neighbors parked car in their driveway. Luckily it was a very low rate of speed so there was minimal damage and nobody was hurt. There were no warning lights present before, during, or after the incident. The vehicle got towed to a local GMC dealership who could not replicate the issue. Insurance is still looking into the issue.