Hackers were able to gain access to contact numbers and email addresses of high-profile users on Instagram due to a bug in the app’s API (application programming interface) used to communicate with other apps. It is likely the same bug was exploited a few days ago when the app’s most-followed user, Selena Gomez, was hacked and nude photos of ex-boyfriend Justin Bieber were posted from her account.

The company has notified all verified account holders that their information may have been leaked, and encouraged them to be cautious of unrecognised phone calls, texts, or emails, reports The Verge.

“We recently discovered that one or more individuals obtained unlawful access to a number of high-profile Instagram users’ contact information — specifically email address and phone number — by exploiting a bug in an Instagram API,” the company said in a statement. “No account passwords were exposed. We fixed the bug swiftly and are running a thorough investigation.”

The Facebook-owned app did not say which accounts had been hit by the exploit, or provide a number on how many accounts had been affected. Whatever the numbers are, and though the breach isn’t as bad as it could’ve been, these security concerns could be a problem for Instagram, especially amongst its high-profile users. The company has seen explosive growth in the past year – losing big names would have a bearing on this – and has worked to make its platform more transparent when it comes to influencer marketing, making it more appealing to marketers, celebrities, social media stars, and normal users alike.