Are you sure it's the boot? Looks to me like the leak is from above and coming down. A boot typically sprays it in a circle (so I'd expect to see grease just about everywhere on the wheel, from it spraying on the wheel during a turn).

Though I can't tell for sure.

Edit... I do see it on the rim now, so yea, could very well be the boot. That said, if the CV isn't making noise yet, let it ride.

Nice light by the way. What color is it? Everything doesn't look super white, so maybe in the 4k range?