Bad News:
If you use Facebook app and you gave that apps an access to your profile, you might want to read this. Usually, such the apps need to access your profile from times to times (e.g., post on the wall). The apps do not use your password to access your profile. They use Facebook-issued tokens to access your profile. The bad news is these token are leaked. Now, hackers can do whatever your apps can do.
Good News:
The fix is simple just change your Facebook's password. Then, Facebook will reissue the tokens to all your apps. The old tokens that hackers might get a hold of would expire.
Wanna know more?
You can read this link to find out the details.
