Review reviewHigh

CVE-2026-33216

nats-io nats-server, Multicluster Global Hub 1.5.4, Red Hat multicluster global hub 1.4.4

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.

CVSS: 7.5
EPSS: 0.36%
CISA KEV: Not listed
Published: 2026.03.26

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.36%

Technical severityCVSS 7.5

Vulnerability overview

Affected product and versions

Product: nats-io nats-server, Multicluster Global Hub 1.5.4, Red Hat multicluster global hub 1.4.4
Affected versions: >= < 2.11.15, >= >= 2.12.0-RC.1, < 2.12.6, < 2.11.15, >= 2.12.0 < 2.12.6
Fixed versions: 2.11.15, 2.12.6

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that nats-io nats-server, Multicluster Global Hub 1.5.4, Red Hat multicluster global hub 1.4.4 and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CWE: CWE-213, CWE-256