Description
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.
References (7)
Core 7
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/nats-io/nats-server/security/advisories/GHSA-38x3-76xf-cq45
X_Refsource_Misc x_refsource_misc
https://github.com/nats-io/nats-server/commit/7b81dd455ea95960090a84858c7662827948d1b6
X_Refsource_Misc x_refsource_misc
https://github.com/nats-io/nats-server/commit/8b8e1ad4ceed32321e00d4fc6e76be05bc13bca6
X_Refsource_Misc x_refsource_misc
https://github.com/nats-io/nats-server/commit/b86147e81710a52b72a7f7275f91d69f723f5cb3
X_Refsource_Misc x_refsource_misc
https://github.com/nats-io/nats-server/releases/tag/v2.11.16
X_Refsource_Misc x_refsource_misc
https://github.com/nats-io/nats-server/releases/tag/v2.12.7
X_Refsource_Misc x_refsource_misc
https://github.com/nats-io/nats-server/releases/tag/v2.14.0
Scores
CVSS v3
8.8
EPSS
0.0039
EPSS Percentile
31.0%
Attack Vector
ADJACENT_NETWORK
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-287
Status
published
Products (3)
linuxfoundation/nats-server
< 2.11.16
nats-io/nats-server
< 2.11.16
nats-io/nats-server
>= 2.12.0-preview.1, < 2.12.6
Published
Jul 08, 2026
Tracked Since
Jul 09, 2026