Cudy WR3000 2.0 running firmware before 2.5.24 contains a hard-coded JWT HMAC signing secret vulnerability in the Mosquitto MQTT broker's authentication plugin that allows unauthenticated attackers to forge valid JWT tokens by extracting the secret from the firmware image. Attackers can use the extracted secret to craft arbitrary JWT tokens and authenticate to the MQTT broker without legitimate credentials, gaining unauthorized access to the device's mesh networking interface.