CVE-2026-58208

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

Published: Jul 8, 2026Updated: Jul 9, 2026 Sources: CVE List NVDCWE-248

6.8MEDIUM

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.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:HAttack Complexity

High

PR:NPrivileges Required

None

UI:NUser Interaction

None

Scope

S:CScope

Changed

Impact

C:NConfidentiality

None

I:NIntegrity

None

A:HAvailability

High

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Weaknesses

CWE-248

Affected Products

nats-io

oss-project

nats-serverOn-prem

Databases / cache-message-queue

linuxfoundation

oss-project·USaka yocto, everest, pytorch

nats-serverOn-premDatabase

AI / ML / vector-db-rag

Exploitability

Official Patch Available

Workaround Available

References

https://github.com/nats-io/nats-server/security/advisories/GHSA-p957-7v2w-g93g

github.com

https://github.com/nats-io/nats-server/commit/73b3dd9a5ea0fa7bf08b702338676355b29b5fb4

github.com

https://github.com/nats-io/nats-server/commit/837536b98b3a9280b993282155ff2bdd3ca38c30

github.com

and 2 more references View all →

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