Apple users are being urged to hold off on updating their phones after a recent update left them vulnerable to hackers.
Fast Company reported about the "nasty location privacy bug" on Friday, saying iOS 13 isn't "respecting" location privacy settings for some apps.
The security flaw meant phones were open to malicious activity, with the potential for hackers to obtain access to contact details, reports Forbes.
Apple is in the process of amending the issue - with the release of iOS 13.1 due to come out on Tuesday (US time).
Until then, users should be aware that location privacy settings may not be being respected, an iOS app developer told Fast Company.
Writing for Forbes, cybersecurity journalist Kate O'Flaherty says the bug was affecting apps such as Facebook.
"It does not impact all apps in iOS 13," she says.
"If you haven't upgraded to iOS 13 yet, it's probably better to wait - when this and a number of other fixes will be applied."
Last month, Forbes reported about a "critical security flaw" in iOS 12.4, saying some iPhones, iPads and iPod touches were vulnerable following the update. Apple was forced to urgently release a patch.