HIGHCVE-2026-33217Published Modified CNA GitHub_M
CVE-2026-33217: NATS allows MQTT clients to bypass ACL checks
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, when using ACLs on message subjects, these ACLs were not applied in the `$MQTT.>` namespace, allowing MQTT clients to bypass ACL checks for MQTT subjects. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.
Metrics
- CVSS v3.1
- 7.1
- Severity
- HIGH
- Fixed in
- —
- Affected Products
- 1
Affected packages
- nats-io / nats-server< 2.11.15 · >= 2.12.0-RC.1, < 2.12.6
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N