CVE-2026-33356: Meari IoT Cloud Mqtt Broker Emqx

High severity, CVSS 7.7. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• Meari IoT Cloud Mqtt Broker Emqx: from 4, before 5 (fixed in 5)

Published 2026-05-11. Last modified 2026-06-17.