# CVE-2026-58211: nats-server: NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system

CVE-2026-58211 is fixed in nats-server on 1 platform by DEBIAN-CVE-2026-58211 (version 2.14.3-1), released July 6, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-58211
- Priority: Routine
- CVSS: 5.4 (medium)
- EPSS: 0.0029
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 8, 2026

## 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 client could be registered as the configured no_auth_user through a parser path used when the first client operation was not CONNECT, bypassing user-level connection restrictions such as allowed_connection_types or proxy_required that normal authentication would apply. This issue is fixed in versions 2.14.3 and 2.12.12.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | nats-server Debian 14 | 2.14.3-1 | [DEBIAN-CVE-2026-58211](https://patchblox.com/security/data/fix/linux/debian-cve-2026-58211.md) | Jul 6, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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