CVE-2026-58208
Medium
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.
SeverityMedium
CVSS6.8
Exploit probability—
ProductLinuxfoundation Nats-server
PublishedJul 8, 2026
First seenJul 8, 2026
Weakness typeCWE-248CWE-248
How to fix
Update
- linuxfoundation nats-server2.12.12, 2.14.3 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linuxfoundation nats-server | 2.12.0 ≤ v < 2.12.12, 2.14.0 ≤ v < 2.14.3 | 2.12.12, 2.14.3 |
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