An authentication issue was addressed with improved state management. This issue is fixed in AirPods Firmware Update 6A326, AirPods Firmware Update 6F8, and Beats Firmware Update 6F8. When your headphones are seeking a connection request to one of your previously paired devices, an attacker in Bluetooth range might be able to spoof the intended source device and gain access to your headphones.
https://support.apple.com/kb/HT214111