Some Snapchat users have been affected by spam after user profiles were hijacked and used to send out ads for a weight loss website, according to the BBC.
The company said its service had not been hacked and the problem occurred due to credentials being sourced from other websites.
“We have seen evidence that hackers who have access to a trove of credentials, leaked from other websites, have started using them to gain access to Snapchat accounts,” the company told the BBC.
While it is unclear how many people were affected by the spam, users in several countries complained about the issue via Twitter.
An image promoting weight loss products was sent to contacts belonging to those whose accounts were breached. Users who subsequently logged back into their accounts were emailed by Snapchat, warning them to change their password.
Snapchat suffered a privacy breach at the beginning of the year when 4.6 million usernames and phone numbers were leaked. The details appeared on the SnapchatDB website with the last two digits of phone numbers redacted.
The group behind SnapchatDB said it published the data to raise awareness of a vulnerability in the service. Snapchat subsequently updated its Android and iOS products to better protect the privacy of users.
Snapchat reportedly secured funding in August that valued the company at around $10 billion. The service reached 100 million monthly active users at around the same time.
Although it is yet to generate revenue, Snapchat is proving attractive to investors due to its popularity with young users. It claims that more than 700 million pictures are sent via its service and more than 500 million stories viewed every day. Along with the recent addition of text, there are signs that Snapchat is looking to monetise its service, with reports that it is to gain new functionality, including support for advertising.