CVE-2026-58208

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

08/07/2026

Last modified:

09/07/2026

Description

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, a WebSocket listener could route requests for the MQTT-over-WebSocket path into MQTT handling even when MQTT was not configured, allowing an unauthenticated client with access to the WebSocket listener to reach uninitialized MQTT state and crash the server process. This issue is fixed in versions 2.14.3 and 2.12.12.

Impact

Vector 3.x

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

Base Score: 6.80 MEDIUM
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H

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

Base Score 3.x

6.80

Severity 3.x

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:linuxfoundation:nats-server::::::::	2.12.0 (including)	2.12.12 (excluding)
cpe:2.3:a:linuxfoundation:nats-server::::::::	2.14.0 (including)	2.14.3 (excluding)

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

CVE-2026-58208

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools