Samsung has confirmed a major security flaw with the in-screen fingerprint scanner in its Galaxy S10 and S10 plus smart phones.The flaw was first discovered by a consumer who put a screen protector on their phone. After that, any fingerprint would unlock the device.It's thought that screen protectors can create an air pocket that interferes with the screens fingerprint scanner.Samsung says all users should switch to passcode unlock and other security features while they investigate how to fix the bug.