Anyone?

 

Power steering fluid reservoir. Never personally seen one overflow but technically if there was a blockage in the feed side of the line it could push the contents of the system back into the reservoir. Use a turkey baster to empty the contents, inspect the reservoir for debris. Have you been having any power steering issues lately?

 

There is sometimes a screen in the bottom of those reservoirs that gets gummed up and blocks flow of the fluid out of it. Use a turkey baster as cleric mentioned to get all of the fluid out and clean it out. Might be time to do a power steering system flush.