CVE-2026-58211
published 2026-07-08CVE-2026-58211: 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…
PriorityP433medium5.4CVSS 3.1
AVNACLPRLUINSUCLILAN
EPSS
0.29%
21.5th 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 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.
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
nvdv3.15.4MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
vendor_redhat5.4MEDIUM
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
Red Hat
nats-server: NATS Server: Authentication bypass allows unauthorized access and information disclosure
vendor_redhat·2026-07-08·CVSS 5.4
CVE-2026-58211 [MEDIUM] CWE-305 nats-server: NATS Server: Authentication bypass allows unauthorized access and information disclosure
nats-server: NATS Server: Authentication bypass allows unauthorized access and information disclosure
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.
A flaw was found in NATS Server, a high-performance messaging system. This vulnerability allows a client to bypass normal authentication and connection restrictions by registering as a "no_auth_user" through a specific parser path. This occurs w
VulDB
nats-io nats-server up to 2.12.11/2.14.2 Parser improper authentication
vuldb·2026-07-08·CVSS 5.4
CVE-2026-58211 [MEDIUM] nats-io nats-server up to 2.12.11/2.14.2 Parser improper authentication
A vulnerability was found in nats-io nats-server up to 2.12.11/2.14.2 and classified as critical. The impacted element is an unknown function of the component Parser. The manipulation results in improper authentication.
This vulnerability is known as CVE-2026-58211. It is possible to launch the attack remotely. No exploit is available.
No detection rules found.
No public exploits indexed.
2026-07-08
Published