NATS has MQTT plaintext password disclosure
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-256.
Summary
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, for MQTT deployments using usercodes/passwords: MQTT passwords are incorrectly classified as a non-authenticating identity statement (JWT) and exposed via monitoring endpoints. Versions 2.11.14 and 2.12.6 contain a fix. As a workaround, ensure monitoring end-points are adequately secured. Best practice remains to not expose the monitoring endpoint to the Internet or other untrusted network users.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| backstage | nats-server | before 2.11.15; 2.12.0-RC.1 to before 2.12.6 | 2.11.15, 2.12.6 | Patch available | CNA |
| — | github.com/nats-io/nats-server/v2 (Go) | before 2.11.15 | 2.11.15 | Patch available | GHSA-v722-jcv5-w7mc |
| — | github.com/nats-io/nats-server/v2 (Go) | 2.12.0-RC.1 to before 2.12.6 | 2.12.6 | Patch available | GHSA-v722-jcv5-w7mc |
| — | github.com/nats-io/nats-server (Go) | all versions | — | No fix listed | GHSA-v722-jcv5-w7mc |
- nats-server Vendorbackstage Affected before 2.11.15; 2.12.0-RC.1 to before 2.12.6 Fixed in 2.11.15, 2.12.6 Patch available CNA
- github.com/nats-io/nats-server/v2 (Go) Vendor— Affected before 2.11.15 Fixed in 2.11.15 Patch available GHSA-v722-jcv5-w7mc
- github.com/nats-io/nats-server/v2 (Go) Vendor— Affected 2.12.0-RC.1 to before 2.12.6 Fixed in 2.12.6 Patch available GHSA-v722-jcv5-w7mc
- github.com/nats-io/nats-server (Go) Vendor— Affected all versions Fixed in — No fix listed GHSA-v722-jcv5-w7mc
Remediation
- Fix · CNA nats-server (nats-io) Fixed in 2.11.15, 2.12.6
- Fix · GHSA-v722-jcv5-w7mc github.com/nats-io/nats-server/v2 (Go) Fixed in 2.11.15 Advisory →
- Fix · GHSA-v722-jcv5-w7mc github.com/nats-io/nats-server/v2 (Go) Fixed in 2.12.6 Advisory →
Red Hat 3 advisories
- RHSA-2026:23345 Released 2026-06-04 · Red Hat rating ImportantMulticluster Global Hub 1.6.2 security update
- Multicluster Global Hub 1.6.6 registry.redhat.io/multicluster-globalhub/multicluster-globalhub-agent-rhel9, registry.redhat.io/multicluster-globalhub/multicluster-globalhub-grafana-rhel9, registry.redhat.io/multicluster-globalhub/multicluster-globalhub-manager-rhel9 +1
- RHSA-2026:22347 Released 2026-06-01 · Red Hat rating ImportantMulticluster Global Hub 1.4.5 security update
- Multicluster Global Hub 1.4.9 registry.redhat.io/multicluster-globalhub/multicluster-globalhub-agent-rhel9, registry.redhat.io/multicluster-globalhub/multicluster-globalhub-grafana-rhel9, registry.redhat.io/multicluster-globalhub/multicluster-globalhub-manager-rhel9 +1
- RHSA-2026:21769 Released 2026-05-28 · Red Hat rating ImportantMulticluster Global Hub 1.5.4 security update
- Multicluster Global Hub 1.5.8 registry.redhat.io/multicluster-globalhub/multicluster-globalhub-agent-rhel9, registry.redhat.io/multicluster-globalhub/multicluster-globalhub-grafana-rhel9, registry.redhat.io/multicluster-globalhub/multicluster-globalhub-manager-rhel9 +1
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Multicluster Global Hub 1.4.9 | Fixed | RHSA-2026:22347 |
| Multicluster Global Hub 1.6.5 | Fixed | RHSA-2026:23345 |
| Red Hat multicluster global hub 1.5.3 | Fixed | RHSA-2026:21769 |
Not affected: 4 products
- Multicluster Global Hub 1.4.9
- Multicluster Global Hub 1.6.5
- Red Hat OpenShift Container Platform 4
- Red Hat multicluster global hub 1.5.3
Timeline
- 2026-10-02 Threatist record created from CVE-2026-33216
- 2026-10-03 Alias added: GHSA-v722-jcv5-w7mc
- 2026-10-23 EPSS moved to the 50th–90th percentile
- 2026-10-25 EPSS moved to the below the 50th percentile
References
Advisory 3
More backstage Nats-server vulnerabilities
- TI-2026-22233 NATS: Pre-auth remote server crash via WebSocket frame length overflow in wsRead CVSS 3.1HIGH 7.5
- TI-2022-11116 NATS nats-server 2.2.0 through 2.7.4 allows directory traversal because of an unintended… CVSS 3.1CRITICAL 9.8
- TI-2020-16319 The JWT library in NATS nats-server before 2.1.9 has Incorrect Access Control because of… CVSS 3.1CRITICAL 9.8
- TI-2022-08320 NATS nats-server before 2.7.2 has Incorrect Access Control. CVSS 3.1HIGH 8.8
- TI-2026-41950 NATS Server: Pre-auth server crash via double INFO in leafnode handshake CVSS 3.1HIGH 7.5
- TI-2026-41920 NATS Server: MQTT partial CONNECT packets can exhaust pre-auth memory CVSS 3.1HIGH 7.5
Sources
- CVE-2026-33216 · CVE Program
- CVE-2026-33216 · NVD
- FIRST EPSS
- GHSA-v722-jcv5-w7mc · GitHub Advisory Database · CC BY 4.0
- CVE-2026-33216 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences