CVE-2026-33249

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

25/03/2026

Last modified:

26/03/2026

Description

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.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N CVSS v3.1 Severity and Metrics:

Base Score: 4.30 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): Low
Availability (A): None

Base Score 3.x

4.30

Severity 3.x

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:linuxfoundation:nats-server::::::::	2.11.0 (including)	2.11.15 (excluding)
cpe:2.3:a:linuxfoundation:nats-server::::::::	2.12.0 (including)	2.12.6 (excluding)

To consult the complete list of CPE names with products and versions, see this page

CVE-2026-33249

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools