CVE-2026-58208 — NATS Server: MQTT-over-WebSocket Path Can Crash WebSocket-Only JetStream Servers Before MQTT Is Enabled
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 …
Published: 2026-07-08 · CVSS: 6.8 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7