CVE-2026-33356 Meari MQTT broker missing per-device subscribe ACL
Authenticated users can subscribe to global topics to read telemetry from devices they do not own due to missing per-device subscribe ACLs.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-33356?
CVE-2026-33356 is a high-severity missing authorization vulnerability in Meari IoT Cloud MQTT Broker EMQX, published on 11 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-639
Which versions are affected by CVE-2026-33356?
How do I fix CVE-2026-33356?
No fix has been published for CVE-2026-33356 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-33356 being exploited?
There is no known exploitation of CVE-2026-33356 in the wild and no public exploit code.
Sources
Also known as GHSA-2vfr-ch7v-7754.