CVE-2026-33216

High

Description

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.

SeverityHigh
CVSS8.6
Exploit probability—
ProductLinuxfoundation Nats-server
PublishedMar 25, 2026
First seenMar 25, 2026
Weakness typeCWE-256CWE-256

How to fix

Update
  • linuxfoundation nats-server2.11.15, 2.12.6 or later
  • github.com/nats-io/nats-server/v22.11.15, 2.12.6 or later

Affected products

ProductAffected versionsFixed in
linuxfoundation nats-serverv < 2.11.15, 2.12.0 ≤ v < 2.12.62.11.15, 2.12.6
github.com/nats-io/nats-server/v2Gov < 2.11.15, 2.12.0-RC.1 ≤ v < 2.12.62.11.15, 2.12.6
github.com/nats-io/nats-serverGoNo range specified—

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