A user in a Russian forum says that he has hacked and uploaded almost 6.5 million LinkedIn passwords, according to The Verge. Though his claim has yet to be confirmed, Twitter users are already reporting that they’ve found their hashed LinkedIn passwords on the list, security expert Per Thorsheim said.

LinkedIn revealed through its own tweet that it’s looking into reports of stolen passwords, and it advised users to stay tuned for more information.

The report of the leaked passwords comes hard on the heels of word from security researchers that LinkedIn’s iOS app is collecting information from calendar entries — including passwords — and transmitting it back to the company’s servers without users’ knowledge.

To change your LinkedIn password, log onto your account. Click on your name in the upper right corner and then click on the link for Settings. In the Settings section, click on the Change link next to Password. You’ll be prompted to to enter your old password and then create a new one. Aim to pick a complex password that’s not easy to decipher. Then click on the Change Password button.

CNET contacted LinkedIn for further details and will update the story when we get more information.