CVE-2026-58253

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when no_auth_user was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an unauthenticated peer to bypass inter-server CONNECT authentication and operate with the privileges associated with that connection type. This issue is fixed in versions 2.14.0, 2.12.7, and 2.11.16.

CVSS v3 8.8 HIGH

8.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.3

Attack Vector ADJACENT_NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact HIGH

Availability Impact LOW

Scope CHANGED

References

Link	Resource
https://github.com/nats-io/nats-server/commit/7b81dd455ea95960090a84858c7662827948d1b6	Patch
https://github.com/nats-io/nats-server/commit/8b8e1ad4ceed32321e00d4fc6e76be05bc13bca6	Patch
https://github.com/nats-io/nats-server/commit/b86147e81710a52b72a7f7275f91d69f723f5cb3	Patch
https://github.com/nats-io/nats-server/releases/tag/v2.11.16	Release Notes
https://github.com/nats-io/nats-server/releases/tag/v2.12.7	Release Notes
https://github.com/nats-io/nats-server/releases/tag/v2.14.0	Release Notes
https://github.com/nats-io/nats-server/security/advisories/GHSA-38x3-76xf-cq45	Vendor Advisory

Configurations

Configuration 1 (hide)

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

History

No history.

Information

Published : 2026-07-08 20:16

Updated : 2026-07-13 15:25

NVD link : CVE-2026-58253

Mitre link : CVE-2026-58253

CVE.ORG link : CVE-2026-58253

JSON object : View

Products Affected

linuxfoundation

nats-server

CWE

CWE-287

Improper Authentication

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