CVE-2026-58208

MEDIUM

NATS Server: MQTT-over-WebSocket Path Can Crash WebSocket-Only JetStream Servers Before MQTT Is Enabled

Title source: cna
STIX 2.1

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.

References (5)

Core 5

Scores

CVSS v3 6.8
EPSS 0.0059
EPSS Percentile 44.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-248
Status published
Products (3)
linuxfoundation/nats-server 2.12.0 - 2.12.12
nats-io/nats-server < 2.12.12
nats-io/nats-server >= 2.14.0-RC.1, < 2.14.3
Published Jul 08, 2026
Tracked Since Jul 09, 2026