CVE-2026-33356

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

11/05/2026

Last modified:

13/05/2026

Description

In Meari IoT Cloud MQTT Broker deployments running EMQX 4.x, any authenticated low-privilege account can subscribe to global wildcard topics and receive telemetry from devices the user does not own. The broker enforces publish restrictions but does not enforce equivalent subscribe authorization at per-device scope.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N CVSS v3.1 Severity and Metrics:

Base Score: 7.70 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): High
Integrity (I): None
Availability (A): None

Base Score 3.x

7.70

Severity 3.x

HIGH

References to Advisories, Solutions, and Tools

https://github.com/xn0tsa/nobody-puts-baby-in-a-corner
https://www.runzero.com/advisories/meari-mqtt-broker-missing-per-device-subscribe-acl-cve-2026-33356/