If I were you, I wouldn't send them an updated CV. Instead, let the strength of the CV you sent them speak for itself.
If I were you, I would keep this ace up my sleeve. If either of these applications leads to an invitation for an interview, you might be asked to give a presentation. That would be the ideal moment to tell them: "look, just after I sent you my application, this other paper of mine also got accepted at a top-level journal".
I wouldn't say it's necessarily inappropriate to send an updated CV, but the message this would send to me is "I'm not confident in the strength of my initial CV, so I need to tell you immediately of anything that can boost it". I don't think it's wise to do this. Conversely, if you can tell them in the interview that you achieved more between the application moment and the interview moment, you show that your CV is even stronger than the committee/professors already thought when they invited you for the interview.