CVE-2026-58211
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 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.
SeverityMedium
CVSS5.4
Exploit probability—
ProductLinuxfoundation Nats-server
PublishedJul 8, 2026
First seenJul 8, 2026
Weakness typeCWE-863Incorrect authorization
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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