CVE-2026-33247

What it is

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, if a nats-server is run with static credentials for all clients provided via argv (the command-line), then those credentials are visible to any user who can see the monitoring port, if that too is enabled. The `/debug/vars` end-point contains an unredacted copy of argv. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, configure credentials inside a configuration file instead of via argv, and do not enable the monitoring port if using secrets in argv. Best practice remains to not expose the monitoring port to the Internet, or to untrusted network sources.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-03-25 20:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-09 13:19 UTC Last updatedMost recent change to the record

Details

Published

2026-03-25 20:16 UTC

Last modified

2026-09-09 13:19 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-215

Record status

Modified

Affected

• Linuxfoundation nats-server < 2.11.15
• Linuxfoundation nats-server < 2.12.6

Attack profile CVSS 3.1 · 7.4

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None