Auth bypass in Yosmart Yolink Mqtt Broker

CVE-2025-59449

The YoSmart YoLink MQTT broker through 2025-10-02 does not enforce sufficient authorization controls to prevent cross-account attacks, allowing an attacker to remotely operate affected devices if the attacker obtains the associated device IDs. Because YoLink device IDs are predictable, an attacker can exploit this to gain full control over any other YoLink user's devices.

Vulnerability class: Broken Access Control

EPSS: 0.003 (19.1th percentile) — read the EPSS interpretation.