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 …
Published: 2026-03-25 · CVSS: 7.1 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7