BIT-NATS-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...

GHSA-JXXM-27VP-C3M5 NATS allows MQTT clients to bypass ACL checks

Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The nats-server provides an MQTT client interface. Problem Description When using ACLs on message subjects, these ACLs were not applied in t...

CVE-2025-30215: Missing Authentication for Critical Function

NATS-Server is a High-Performance server for NATS.io, the cloud and edge native messaging system. In versions starting from 2.2.0 but prior to 2.10.27 and 2.11.1, the management of JetStream assets happens with messages in the $JS. subject namespace in the system account; this is partially expose...