CVE-2026-58211

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 "noauthuser" through a specific parser path. This occurs when the client's initial operation is not a standard...

SUSE CVE-2026-58253

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when noauthuser was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an...

CVE-2026-58253

A flaw was found in NATS Server. When the noauthuser configuration is enabled, a parser optimization intended for client connections can inadvertently apply to route or leafnode listeners. This allows an unauthenticated attacker on an adjacent network to bypass inter-server authentication...

CVE-2026-58211

CVE-2026-58211 affects NATS Server. A vulnerable path allows a client to be registered as the configured no_auth_user via a parser path when the first client operation is not CONNECT, bypassing user-level connection restrictions such as allowed_connection_types or proxy_required. This could enabl...

CVE-2026-58211 NATS Server: `no_auth_user` pre-CONNECT fast path bypasses user connection restrictions

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 noauthuser through a parser path used when the first client operation was not CONNECT, bypassing user-level connection...

CVE-2026-58253 NATS Server: Route API Auth Bypass

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when noauthuser was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an...

nats-server: NATS Server: Authentication bypass allows unauthorized access and information disclosure

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 "noauthuser" through a specific parser path. This occurs when the client's initial operation is not a standard...

nats-server: NATS Server: Authentication bypass allows unauthorized access and information disclosure

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 "noauthuser" through a specific parser path. This occurs when the client's initial operation is not a standard...

GO-2023-2133 Authorization bypass in github.com/nats-io/nats-server/v2

Without any authorization rules in the nats-server, users can connect without authentication. Before nats-server 2.2.0, all authentication and authorization rules for a nats-server lived in an "authorization" block, defining users. With nats-server 2.2.0 all users live inside accounts. When using...