CVE-2026-33215

Severity CVSS v4.0:

Pending analysis

Type:

CWE-287 Authentication Issues

Publication date:

24/03/2026

Last modified:

24/03/2026

Description

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The nats-server provides an MQTT client interface. Prior to versions 2.11.15 and 2.12.5, Sessions and Messages can by hijacked via MQTT Client ID malfeasance. Versions 2.11.15 and 2.12.5 patch the issue. No known workarounds are available.

Impact

Vector 3.x

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

Base Score: 6.50 MEDIUM
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L

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

Base Score 3.x

6.50

Severity 3.x

MEDIUM

References to Advisories, Solutions, and Tools

https://advisories.nats.io/CVE/secnote-2026-06.tx
https://github.com/nats-io/nats-server/security/advisories/GHSA-fcjp-h8cc-6879