8.6
HIGH CVSS 3.1
CVE-2026-33216
NATS has MQTT plaintext password disclosure
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.

INFO

Published Date :

March 25, 2026, 8:16 p.m.

Last Modified :

March 25, 2026, 8:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-33216 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH [email protected]
Solution
Update NATS-Server and secure monitoring endpoints to prevent password exposure.
  • Update NATS-Server to version 2.11.15 or later.
  • Update NATS-Server to version 2.12.6 or later.
  • Secure monitoring endpoints from unauthorized access.
  • Do not expose monitoring endpoints to the internet.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-33216.

URL Resource
https://advisories.nats.io/CVE/secnote-2026-05.txt
https://github.com/nats-io/nats-server/commit/b5b63cfc35a57075e09c1f57503d31721bed8099
https://github.com/nats-io/nats-server/security/advisories/GHSA-v722-jcv5-w7mc
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-33216 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-33216 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-33216 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-33216 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Mar. 25, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
    Added CWE CWE-256
    Added Reference https://advisories.nats.io/CVE/secnote-2026-05.txt
    Added Reference https://github.com/nats-io/nats-server/commit/b5b63cfc35a57075e09c1f57503d31721bed8099
    Added Reference https://github.com/nats-io/nats-server/security/advisories/GHSA-v722-jcv5-w7mc
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.