CVE-2026-33216
HIGH8.6EPSS 0.05%NATS has MQTT plaintext password disclosure
Published: 3/24/2026Modified: 4/28/2026
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.
Affected packages (6)
- Bitnami/natsfrom 0, < 2.11.15, >= 2.12.0, < 2.12.6
- Debian/nats-serverfrom 0
- Go/github.com/nats-io/nats-serverfrom 0
- Go/github.com/nats-io/nats-serverfrom 0
- Go/github.com/nats-io/nats-server/v2from 0, < 2.11.15
- Go/github.com/nats-io/nats-server/v2from 0, < 2.11.15, >= 2.12.0-RC.1, < 2.12.6
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N |
References (6)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-33216
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-33216
- PATCHhttps://github.com/nats-io/nats-server
- WEBhttps://advisories.nats.io/CVE/secnote-2026-05.txt
- WEBhttps://github.com/nats-io/nats-server/commit/b5b63cfc35a57075e09c1f57503d31721bed8099
- WEBhttps://github.com/nats-io/nats-server/security/advisories/GHSA-v722-jcv5-w7mc