Having the same issue here.

I work with a help desk that supports a lot of different companies.

So far we've heard from at least 2 of them describing this same issue.

I was at a complete loss as to what was happening until I finally
found this thread. Every time they sent me the jpeg the couldn't open,
I could open it fine. After reading this, I checked and found that I
do not have the security update installed on my computer. After
installing it, the pictures stopped opening on my computer too!

Craziness!!! Microsoft get this fixed ASAP!