Terms were not disclosed.
Cunningham was the 24th overall selection in the NBA draft by the Cleveland Cavaliers. He was acquired by the Mavericks last month, along with the draft rights to Bernard James, the 33rd overall pick, and 34th overall pick Jae Crowder, in exchange for guard Kelenna Azubuike and the draft rights to the 17th overall pick in the draft, Tyler Zeller.
Cunningham is on the Mavericks' Summer League team in Las Vegas, but has not played because of a strained hamstring.
Cunningham was selected first-team All-Pac-12 as a junior when he averaged 17.9 points, 3.8 rebounds, 2.8 assists and 2.5 steals per game for Oregon State.