The ornamental design for a cable accessory, as shown and described.
FIG. 1 is a perspective view of a cable accessory as shown and described;
FIG. 2 is a front view of the cable accessory of FIG. 1;
FIG. 3 is a back view of the cable accessory of FIG. 1;
FIG. 4 is a right view of the cable accessory of FIG. 1;
FIG. 5 is a left view of the cable accessory of FIG. 1;
FIG. 6 is a top view of the cable accessory of FIG. 1; and,
FIG. 7 is a bottom view of the cable accessory of FIG. 1.
The broken lines shown in the drawings showing a cable and ear buds represent environmental matter and all other broken lines illustrate portions of the cable accessory that form no part of the claimed design.