A cutting knife for a cutting tool for cutting through adhesive beads on glass panes of vehicles comprises an attachment part and a cutting part. The attachment part, on a first end thereof, is provided with a receiving opening for attachment to an oscillating drive and taperes toward a second end. The cutting part extends at an angle with respect to a plane in which the flat attachment part extends. The cutting part has two lateral edges that join each other at the outer end of the cutting part, at least one of the lateral edges of the cutting part being shaped as a corrugated or serrated cutting edge.