Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linuxfoundation | Nats-Server | >= 2.12.0, < 2.12.12 |
Related Weaknesses (CWE)
References
- https://github.com/nats-io/nats-server/commit/73b3dd9a5ea0fa7bf08b702338676355b2Patch
- https://github.com/nats-io/nats-server/commit/837536b98b3a9280b993282155ff2bdd3cPatch
- https://github.com/nats-io/nats-server/releases/tag/v2.12.12Release Notes
- https://github.com/nats-io/nats-server/releases/tag/v2.14.3Release Notes
- https://github.com/nats-io/nats-server/security/advisories/GHSA-p957-7v2w-g93gMitigationVendor Advisory
FAQ
What is CVE-2026-58208?
CVE-2026-58208 is a vulnerability with a CVSS score of 6.8 (MEDIUM). 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 pat...
How severe is CVE-2026-58208?
CVE-2026-58208 has been rated MEDIUM with a CVSS base score of 6.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-58208?
Check the references section above for vendor advisories and patch information. Affected products include: Linuxfoundation Nats-Server.