CVE-2026-58211

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 client could be registered as the configured no_auth_user through a parser path used when the first client operation was not CONNECT, bypassing user-level connection restrictions such as allowed_connection_types or proxy_required that normal authentication would apply. This issue is fixed in versions 2.14.3 and 2.12.12.

CVSS v3 5.4 MEDIUM

5.4^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/nats-io/nats-server/security/advisories/GHSA-hmmp-q8cx-v964	Mitigation Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:linuxfoundation:nats-server::::::::
	cpe:2.3:a:linuxfoundation:nats-server::::::::

History

09 Jul 2026, 19:00

Type	Values Removed	Values Added
CPE		cpe:2.3:a:linuxfoundation:nats-server::::::::
First Time		Linuxfoundation nats-server Linuxfoundation
References	~~() https://github.com/nats-io/nats-server/security/advisories/GHSA-hmmp-q8cx-v964 -~~	() https://github.com/nats-io/nats-server/security/advisories/GHSA-hmmp-q8cx-v964 - Mitigation, Vendor Advisory

08 Jul 2026, 21:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-08 21:16

Updated : 2026-07-09 19:00

NVD link : CVE-2026-58211

Mitre link : CVE-2026-58211

CVE.ORG link : CVE-2026-58211

JSON object : View

Products Affected

linuxfoundation

nats-server

CWE

CWE-863

Incorrect Authorization

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