According to the Boston Globe's Dan Shaughnessy, a source has told him that the Chicago Cubs have asked the Boston Red Sox permission to speak with GM Theo Epstein. Since Epstein is still under contract with the Red Sox, they can refuse the Cubs request if they chose to do so. Of course, Epstein himself can decline.
I still am having a hard time believing the Red Sox would let Epstein go. Replacing talented front office personal is hard to do and the Red Sox themselves have already felt the impact of losing quality people (Jed Hoyer to name someone).
Losing Epstein would be a big blow to an organization that is in a little bit of flux right now.