A cable bushing intended to close off, in a sealed way, a space around a plurality of cables, comprises a first compression part (4) intended to be positioned towards the outside of a sleeve (47), a second compression part (6), offset in a longitudinal direction from the first compression part (4) and intended to be positioned toward the inside of the sleeve (47), a plurality of openings (8, 9, 11, 12) formed in the first compression part (4) and a plurality of corresponding openings (13, 14, 16, 17) formed in the second compression part (6), each of the said openings (8, 9, 11, 12) in the first compression part (4) being intended, together with the corresponding openings (13, 14, 16, 17) in the second compression part (6) for a respective cable to pass through, sealing means (7) located between the said first compression part (4) and the said second compression part (6), and compression means for moving the first compression part (4) and second compression part (6) towards one another in the longitudinal direction to compress the sealing means (7). The said first compression part (4) and the said second compression part (6) each comprise, for each opening (8, 9, 11, 12, 13, 14, 16, 17) therein, at least one piece (19, 21, 22, 23, 24, 26, 27, 28) that is movable to provide access individually to the respective opening (8, 9, 11, 12, 13, 14, 16, 17).