Whose the “unidentified third party” in the DoorDash breach?

I’m soooooo curious. I’m suspicious of an authentication partner (fb, auth0, etc) especially because nobody will say shit about the partner... but no clue. Anybody w actual knowledge? I got an email this morning that CafePress was hacked as well (forgot I even had a CafePress account...) Probably unrelated, but ... coolsies.