wpte
100% cpu usage already fixed in r3479 It is a bug inside miniupnpd. I would be glad if someone opened a problem at miniupnpd's forum, I haven't enough time for it.

True root of problem should be investigated, but I can't reproduce this bug myself. Probably, recipient close other end of pipe too early and miniupnpd either don't parse response correctly or it is an hole in workflow...