A cable sleeve includes a covering body having a front-face end defining a circumferential, conically tapered flange. At least one front-face sealing body is positioned adjacent the covering body and has a circumferential, U-shaped sealing groove. A ring seal in inserted into the sealing groove of the sealing body. The ring seal has an L-shaped cross-section and has a first leg that received within the sealing groove of the sealing body and a second leg having a tapered course on both sides broadening towards the first leg. A straining ring fastens the ring seal between the flange of the covering body and the sealing groove of the sealing body.