The WindowsHello open source library (NuGet HaemmerElectronics.SeppPenner.WindowsHello), before version 1.0.4, has a vulnerability where encrypted data could potentially be decrypted without needing authentication. If the library is used to encrypt text and write the output to a txt file, another executable could be able to decrypt the text using the static method NCryptDecrypt from this same library without the need to use Windows Hello Authentication again. This has been patched in version 1.0.4.

Internal NCryptDecrypt method could be used externally from WindowsHello library.