A cutting insert for a tool for machining a workpiece, comprising a first cutting edge and a first cutting insert bore, wherein the cutting insert has an elongate shape and extends along a cutting insert longitudinal direction, wherein the first cutting insert bore extends along a first bore axis, which runs substantially orthogonally to the cutting insert longitudinal direction, wherein the cutting insert has a laterally protruding elevation, which is arranged on a side of the cutting insert that is oriented transversely to the first bore axis, and wherein on the elevation are arranged a first lateral holder contact surface, an axial holder contact surface and a first horizontal holder contact surface for the bearing contact of the cutting insert against a tool holder, wherein the first lateral holder contact surface runs substantially orthogonally to the first bore axis, and wherein the axial holder contact surface and the first horizontal holder contact surface run substantially orthogonally to the first lateral holder contact surface and transversely to each other.