YubiKey NEO and YubiKey NEO-n devices have shipped with firmware version 3.3 since Oct. 1, 2014. This version includes U2F support along with other protocols including Yubico OTP and smart card functionality.

YubiKey NEOs cannot be upgraded based on best security practices. There is a “no upgrade” policy for our devices since nothing, including malware, can write to the firmware.

For more information, see our blog post YubiKey and BadUSB.