Cabin door assembly for a lift, having a mechanical cabin door lock, comprising: - a pivotably mounted articulated part which is assigned to the cabin door and which is designed to support at least one driver blade (14a, 14b), the at least one driver blade (14a, 14b) in turn being designed to engage, in the region of an unlocking zone of the lift, with at least one counter-element (16a, 16b) which is assigned to a shaft door, for joint opening and closing of the cabin door and the shaft door, at least one stop element also being assigned to the articulated part; - a restoring element which interacts directly or indirectly with the pivotable articulated part in such a way that said articulated part is preloaded in a direction counter to a first end position; - a drive device which is designed, when actuated in the unlocking zone, to interact with the articulated part in such a way that, for joint opening of the cabin door and the shaft door, the articulated part is first pivoted in the direction of the action of the restoring element as far as an engagement position of the at least one driver blade (14a, 14b) with the at least one counter-element (16a, 16b), and then the articulated part is moved linearly, and, for joint closing of the cabin door and the shaft door, the articulated part is first moved linearly and then the articulated part is pivoted counter to the direction of the action of the restoring element; characterised in that the articulated part is also mounted in such a way that, in the event of a failure of the drive device outside the unlocking zone, it passes over the engaged position as a result of the action of the restoring element and reaches a second end position; - a first and a second catch element (22, 24), each of which is arranged and designed in such a way that in the first end position of the articulated part, a linear movement of the articulated part in the opening direction of the cabin door is limited to a first opening path by an interaction of the or one of the stop elements with the first catch element, and in the second end position of the articulated part, a linear movement of the articulated part in the opening direction of the cabin door is limited to a second opening path by an interaction of the or one of the stop elements with the second catch element. - a pivotably mounted articulated part which is assigned to the cabin door and which is designed to support at least one driver blade (14a, 14b), the at least one driver blade (14a, 14b) in turn being designed to engage, in the region of an unlocking zone of the lift, with at least one counter-element (16a, 16b) which is assigned to a shaft door, for joint opening and closing of the cabin door and the shaft door, at least one stop element also being assigned to the articulated part; - a restoring element which interacts directly or indirectly with the pivotable articulated part in such a way that said articulated part is preloaded in a direction counter to a first end position; - a drive device which is designed, when actuated in the unlocking zone, to interact with the articulated part in such a way that, for joint opening of the cabin door and the shaft door, the articulated part is first pivoted in the direction of the action of the restoring element as far as an engagement position of the at least one driver blade (14a, 14b) with the at least one counter-element (16a, 16b), and then the articulated part is moved linearly, and, for joint closing of the cabin door and the shaft door, the articulated part is first moved linearly and then the articulated part is pivoted counter to the direction of the action of the restoring element; characterised in that the articulated part is also mounted in such a way that, in the event of a failure of the drive device outside the unlocking zone, it passes over the engaged position as a result of the action of the restoring element and reaches a second end position; - a first and a second catch element (22, 24), each of which is arranged and designed in such a way that in the first end position of the articulated part, a linear movement of the articulated part in the opening direction of the cabin door is limited to a first opening path by an interaction of the or one of the stop elements with the first catch element, and in the second end position of the articulated part, a linear movement of the articulated part in the opening direction of the cabin door is limited to a second opening path by an interaction of the or one of the stop elements with the second catch element.