Third-party apps like Tinder, Spotify and Instagram may also be affected.
Security experts are warning Facebook users to be extra vigilant after it was hacked.
The social media giant's revealed attackers exploited the "View As" feature in July last year - which lets you see your profile as others do.
Ireland's Data Protection Commissioner said it's 'concerned' at the breach and it has contacted Facebook to clarify matters.
Anyone affected is being made to log into their devices again.
