CVE-2026-58208
Published:July 08, 2026
Updated:August 04, 2026
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.
Affected Packages
https://github.com/nats-io/nats-server.git (GITHUB):
Affected version(s) >=v0.5.1 <v2.12.12Fix Suggestion:
Update to version v2.12.12https://github.com/nats-io/nats-server.git (GITHUB):
Affected version(s) >=v2.14.0 <v2.14.3Fix Suggestion:
Update to version v2.14.3github.com/nats-io/nats-server/v2 (GO):
Affected version(s) >=v2.0.0-RC14.0.20190604014547-ed1901c79292 <v2.12.12Fix Suggestion:
Update to version v2.12.12github.com/nats-io/nats-server/v2 (GO):
Affected version(s) >=v2.14.0 <v2.14.3Fix Suggestion:
Update to version v2.14.3Related Resources (7)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.9
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
HIGH
CVSS v3
Base Score:
6.8
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Uncaught Exception
EPSS
Base Score:
0.34