Let me be scrupulously careful here in how I phrase this: There are files ("dumps") on the black market that claim to be from a LiveJournal breach in 2014, and I've never seen anyone who was listed in the dumps say that their information was incorrect (and have seen many who have said it was). However, LiveJournal has never confirmed the breach or informed their users of the problem, so there's a chance the dumps are fake, or that the account info is from another source that the compiler of the file took and tested against LiveJournal to find people whose passwords were reused. We, as a company, are making no statement and have no opinion on whether LiveJournal had a data breach, and we hope that if they had, they would have notified their users.

That having been said, this is exactly why we take every opportunity we can to remind people that it's a bad idea to reuse passwords across sites! If you've ever used your current Dreamwidth password on any other site (not just LiveJournal), please change it. Password managers are a great way to both generate strong, unique passwords and to store those passwords for you so that you don't lose them.