Talking about works under submission without breaching anonymity
The point of blinding authors is to prevent implicit biases from influencing the reviewers' judgements. It's practically impossible to blind properly; reviewers are probably able to deduce your identity if they want to. However, a good reviewer shouldn't want to: they should judge your work by its own merits. Thus, in my opinion you should be able to simply mention the other conferences.

(Also: the value of your work is in the work itself - where it is submitted doesn't add anything to that, it merely signals the value you think it has. Not really relevant to this question, but it might help to sharpen your thinking.)