GHSA-jxxm-27vp-c3m5
NATS allows MQTT clients to bypass ACL checks
At a glance
- Published
- Updated
- CVE
- CVE-2026-33217
- Aliases
- BIT-nats-2026-33217, GO-2026-4834
- CVSS_V3
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
Description
### 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 the `$MQTT.>` namespace, allowing MQTT clients to bypass ACL checks for MQTT subjects. ### Affected Versions Any version before v2.12.6 or v2.11.15 ### Workarounds None.
Affected packages
| Package | Versions |
|---|---|
| Go · github.com/nats-io/nats-server/v2 | introduced 0, fixed 2.11.15 |
| Go · github.com/nats-io/nats-server/v2 | introduced 2.12.0-RC.1, fixed 2.12.6 |
| Go · github.com/nats-io/nats-server | introduced 0 |
References
- https://github.com/nats-io/nats-server/security/advisories/GHSA-jxxm-27vp-c3m5 WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-33217 ADVISORY
- https://advisories.nats.io/CVE/secnote-2026-07.txt WEB
- https://github.com/nats-io/nats-server PACKAGE
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |