It's not causing damage, and Windows Updates always leaves a cache, but this time there's no way to delete the contents which is a good deal larger than normal.

PCWorld hastens to reassure us that in and of itself, the large cache causes no problems, although with so many bugs, I don't know how they can make that claim, responsibly.

Anyway, those who have updated will have to wait for MS to solve this problem. Until then, you're out 9 Gb (8.63 Gb for sticklers) of disk space.