CVE-2026-58208
published 2026-07-08CVE-2026-58208: 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…
PriorityP348high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.60%
46.6th percentile
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.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linuxfoundation | nats-server | >= 2.12.0 < 2.12.12 | 2.12.12 |
| linuxfoundation | nats-server | >= 2.14.0 < 2.14.3 | 2.14.3 |
| nats-io | nats-server | < 2.12.12 | 2.12.12 |
| nats-io | nats-server | — | — |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vendor_redhat7.5HIGH
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Red Hat
github.com/nats-io/nats-server: NATS Server: Denial of Service due to incorrect MQTT-over-WebSocket request routing
vendor_redhat·2026-07-08·CVSS 7.5
CVE-2026-58208 [HIGH] CWE-824 github.com/nats-io/nats-server: NATS Server: Denial of Service due to incorrect MQTT-over-WebSocket request routing
github.com/nats-io/nats-server: NATS Server: Denial of Service due to incorrect MQTT-over-WebSocket request routing
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.
A flaw was found in NATS Server. An unauthenticated client with access to the WebSocket listener could exploit a vulnerability where requests for the MQTT-over-WebSocket path were incorrectly routed into MQTT handling, even when MQTT was
VulDB
nats-io nats-server up to 2.12.11/2.14.2 MQTT uninitialized pointer
vuldb·2026-07-08·CVSS 6.8
CVE-2026-58208 [MEDIUM] nats-io nats-server up to 2.12.11/2.14.2 MQTT uninitialized pointer
A vulnerability was found in nats-io nats-server up to 2.12.11/2.14.2. It has been rated as problematic. Affected is an unknown function of the component MQTT Handler. Performing a manipulation results in uninitialized pointer.
This vulnerability was named CVE-2026-58208. The attack may be initiated remotely. There is no available exploit.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-58208 golang-github-nats-io-streaming-server: NATS Server: Denial of Service due to incorrect MQTT-over-WebSocket request routing [fedora-all]
bugzilla·2026-07-13·CVSS 7.5
CVE-2026-58208 [HIGH] CVE-2026-58208 golang-github-nats-io-streaming-server: NATS Server: Denial of Service due to incorrect MQTT-over-WebSocket request routing [fedora-all]
CVE-2026-58208 golang-github-nats-io-streaming-server: NATS Server: Denial of Service due to incorrect MQTT-over-WebSocket request routing [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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 versio
Bugzilla
CVE-2026-58208 github.com/nats-io/nats-server: NATS Server: Denial of Service due to incorrect MQTT-over-WebSocket request routing
bugzilla·2026-07-08·CVSS 7.5
CVE-2026-58208 [HIGH] CVE-2026-58208 github.com/nats-io/nats-server: NATS Server: Denial of Service due to incorrect MQTT-over-WebSocket request routing
CVE-2026-58208 github.com/nats-io/nats-server: NATS Server: Denial of Service due to incorrect MQTT-over-WebSocket request routing
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.
https://github.com/nats-io/nats-server/commit/73b3dd9a5ea0fa7bf08b702338676355b29b5fb4https://github.com/nats-io/nats-server/commit/837536b98b3a9280b993282155ff2bdd3ca38c30https://github.com/nats-io/nats-server/releases/tag/v2.12.12https://github.com/nats-io/nats-server/releases/tag/v2.14.3https://github.com/nats-io/nats-server/security/advisories/GHSA-p957-7v2w-g93g
2026-07-08
Published