A turbine engine blade includes an airfoil connected by a platform to a middle radial wall extending axially and prolonged radially inwards by a blade root that is mountable in a slot of a disk, and the platform and the middle radial wall defining two lateral cavities situated on either side of the middle radial wall and opening out circumferentially to receive scaling members. The cavities are open downstream with two fins projecting on either side of the middle radial wall at downstream end of the middle radial wall, the fins coming to bear against two adjacent teeth of the disk between which the slot is formed. The downstream end of the middle radial wall includes a setback extending between at least one rib of the platform and the fins.