Management that gossips about colleagues. Tips?

Has anyone dealt with this successfully?

I have a supervisor that talks badly about colleagues that aren’t in the room (things like, she isn’t good at her job, so-and-so is screwing up, and some personal stuff).

The first time she did this she had just been talking sweetly to the manager above her and when he left a few minutes later she was talking shit about him.

When she took over this role, she shared all the “faults” of the previous manager with everyone and I think many of us were uncomfortable because we liked this person and she still works in the company.

Long story short: my direct supervisor talks shit about pretty much everyone I work with, and that includes me (another colleague told me). I do feel crappy whenever I hear the gossip. I have asked my manager if she told people what she was telling me, and the answer is always no.

What to do? Should I go higher up with this since I already told her to talk directly to the people gossiped about? Any advice would be great. Thanks