CVE-2026-33249

What it is

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.11.0 and prior to versions 2.11.15 and 2.12.6, a valid client which uses message tracing headers can indicate that the trace messages can be sent to an arbitrary valid subject, including those to which the client does not have publish permission. The payload is a valid trace message and not chosen by the attacker. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. Limited direct impact.

Exploit odds

0.2% 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 21:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 10:37 UTC Last updatedMost recent change to the record

Details

Published

2026-03-25 21:16 UTC

Last modified

2026-06-17 10:37 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-863 · Incorrect authorization

Record status

Analyzed

Affected

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

Attack profile CVSS 3.1 · 4.3

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None