Facebook says a hack affecting 50 million users could also have given attackers access to other apps.
Facebook’s vice president of product, Guy Rosen, says that attackers with access to a Facebook user’s account could also have accessed other apps if they had logged into them using their Facebook username and password.
A feature called Facebook Login allows people to use their Facebook credentials to sign into certain other apps and services.
Rosen wouldn’t say if there was any evidence that attackers misused access to those third party accounts. He says it could have affected apps tied to someone’s Facebook account, including Facebook’s own Instagram app – although not its WhatsApp messaging service.
He says affected users will now have to manually re-link those third party apps to their Facebook accounts.