Is this privet?
Euonymus fortunei, wintercreeper.
Pretty annoying pest plant around here. As it climbs, it is able to flower/fruit (versus not doing so as a smothering groundcover). Thus, birds eat fruit and deposit everywhere and you get these vines coming up at the base of trees.
OH -- I had read about it before, but didn't make the connection. Yikes. Thanks, VV.