On the remote, press > General > Firmware (if available in your specific regional menu).
A firmware update was released for the Denon AVR-591 that addresses multiple security and stability issues. This report summarizes the patched vulnerabilities, user-impacting changes, update procedure, testing results, and recommendations for administrators and end users. denon avr591 firmware update patched
The Denon AVR-591 is a popular mid-range audio-video receiver from the early 2010s, known for solid build quality and reliable performance. However, as these units age, the term "patched firmware" often appears in troubleshooting forums. This usually refers to one of two scenarios: either a user attempting to modify the firmware to unlock features (region-free hacks) or, more commonly, a user dealing with a unit that has become "bricked" or locked due to a failed official update. On the remote, press > General > Firmware