Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linuxfoundation | Nats-Server | < 2.11.16 |
Related Weaknesses (CWE)
References
- https://github.com/nats-io/nats-server/commit/7b81dd455ea95960090a84858c76628279Patch
- https://github.com/nats-io/nats-server/commit/8b8e1ad4ceed32321e00d4fc6e76be05bcPatch
- https://github.com/nats-io/nats-server/commit/b86147e81710a52b72a7f7275f91d69f72Patch
- https://github.com/nats-io/nats-server/releases/tag/v2.11.16Release Notes
- https://github.com/nats-io/nats-server/releases/tag/v2.12.7Release Notes
- https://github.com/nats-io/nats-server/releases/tag/v2.14.0Release Notes
- https://github.com/nats-io/nats-server/security/advisories/GHSA-38x3-76xf-cq45Vendor Advisory
FAQ
What is CVE-2026-58253?
CVE-2026-58253 is a vulnerability with a CVSS score of 8.8 (HIGH). 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 fo...
How severe is CVE-2026-58253?
CVE-2026-58253 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-58253?
Check the references section above for vendor advisories and patch information. Affected products include: Linuxfoundation Nats-Server.