Snapchat said it is implementing measures to make its app more secure
Snapchat said it will release an updated version of its app after hackers downloaded usernames and phone numbers for 4.6 million accounts.
It said the update will allow users to opt out of appearing in its feature, Find Friends, after they have verified their phone number.
Find Friends allows users to upload their address book contacts to find others who are also using the service.
The hack came after a security firm warned of vulnerabilities in the app.
The security firm, Gibson Security, highlighted the flaw, which it said could be used to reveal the phone numbers of users, in its report published on 25 December.
Snapchat had acknowledged in a blogpost last week that "it was possible for an attacker to use the functionality of Find Friends to upload a large number of random phone numbers and match them with Snapchat usernames".
But it said at that time that it had taken measures to protect users' data.
However, the hackers still managed to download the phone numbers and even temporarily post the data online.
Snapchat said that, along with allowing users to opt out of appearing in Find Friends, it will improve "other restrictions to address future attempts to abuse our service".