ATT's website does not yet mention the update.
After the phone rudely updated without my permission, I can report this:
Android version: 6.0
Android security patch level: 2017-02-01
Kernel Version: 3.10.84
Build number: MRA58K
Software version: H81022d
Security software version: MDF v2.0 release 2
After the phone rudely updated without my permission, I can report this:
Android version: 6.0
Android security patch level: 2017-02-01
Kernel Version: 3.10.84
Build number: MRA58K
Software version: H81022d
Security software version: MDF v2.0 release 2