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

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (18.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 18.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-59449: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-59449?
CVE-2025-59449 is a medium-severity vulnerability in Yosmart Yolink Mqtt Broker, classified under Incorrect Authorization. CVSS score: 4.9/10. Published 2025-10-06.
How severe is CVE-2025-59449?
Medium severity. CVSS v3 base score is 4.9 out of 10.