An information leak was discovered on Yubico YubiKey 5 NFC devices 5.0.0 to 5.2.6 and 5.3.0 to 5.3.1. The OTP application allows a user to set optional access codes on OTP slots. This access code is intended to prevent unauthorized changes to OTP configurations. The access code is not checked when updating NFC specific components of the OTP configurations. This may allow an attacker to access configured OTPs and passwords stored in slots that were not configured by the user to be read over NFC, despite a user having set an access code. (Users who have not set an access code, or who have not configured the OTP slots, are not impacted by this issue.)

A PIN management problem was discovered on Yubico YubiKey 5 devices 5.2.0 to 5.2.6. OpenPGP has three passwords: Admin PIN, Reset Code, and User PIN. The Reset Code is used to reset the User PIN, but it is disabled by default. A flaw in the implementation of OpenPGP sets the Reset Code to a known value upon initialization. If the retry counter for the Reset Code is set to non-zero without changing the Reset Code, this known value can be used to reset the User PIN. To set the retry counters, the Admin PIN is required.