Medium · published September 17, 2026
TCH QRing smart ring model R20_B006 running firmware RT09R20_1.00.00_250318 contains an unauthenticated Bluetooth Low Energy access vulnerability that allows any nearby attacker to connect to the device without pairing, authentication, or user approval by exploiting the exposed Nordic UART Service which enforces no client authentication or command authorization. Attackers within Bluetooth Low Energy range can connect directly to the ring, bypassing the official application and cloud authentication, to read battery levels, activate live heart rate monitoring, and retrieve stored historical heart rate and blood oxygen records.