I have looked all over the internet, unsuccessfully, to identify a new weed in my garden. Hope someone can help!

It's a vine, leaves shaped like grape leaves, stalk more like a squash vine (not strong and tough like a grape, more hollow and wimpy like a squash.) Grows very rapidly and climbs over everything. It produces nasty large clusters of burrs. I think it had a smallish yellow flower (making me think it was some sort of volunteer squash earlier in the season.)

Anyone know what this is?

thanks,

Nell