CVE-2026-58208 NATS Server: MQTT-over-WebSocket Path Can Crash WebSocket-Only JetStream Servers Before MQTT Is Enabled

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...

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-2026-58251

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, an authenticated user with subscription deny permissions could bypass a plain subject deny rule by using a queue subscription, because queue-specific deny...

CVE-2026-58252

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, an authenticated user could receive messages on denied subjects when a wildcard subscription overlapped with a configured wildcard deny rule but was not a subset...

CVE-2026-58210

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, an unauthenticated MQTT client could cause the server to retain large incomplete MQTT CONNECT packets before authentication completed, consuming server memory while the...

CVE-2026-58209

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, MQTT retained message delivery and QoS1+ durable replay could deliver messages whose original topics matched a subscriber configured subscribe deny rule because these...

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-2026-58211

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

CVE-2026-58250

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.12.8 and 2.11.17, an unauthenticated peer with network access to a leafnode listener with compression enabled could crash the server during the pre-authentication leafnode handshake by...

CVE-2026-58251

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, an authenticated user with subscription deny permissions could bypass a plain subject deny rule by using a queue subscription, because queue-specific deny...

CVE-2026-58209

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, MQTT retained message delivery and QoS1+ durable replay could deliver messages whose original topics matched a subscriber configured subscribe deny rule because these...

CVE-2026-58207 NATS Server: Remote crash via integer overflow in Connz pagination

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 able to send account-scoped connection monitoring requests could crash the server by supplying Connz pagination Offset and Limit values that overflowed internal...

CVE-2026-58207

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 able to send account-scoped connection monitoring requests could crash the server by supplying Connz pagination Offset and Limit values that overflowed internal...

CVE-2026-58207 NATS Server: Remote crash via integer overflow in Connz pagination

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 able to send account-scoped connection monitoring requests could crash the server by supplying Connz pagination Offset and Limit values that overflowed internal...

EUVD-2026-42389

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 able to send account-scoped connection monitoring requests could crash the server by supplying Connz pagination Offset and Limit values that overflowed internal...

CVE-2026-58207

CVE-2026-58207 affects NATS Server. A client sending account-scoped Connz pagination requests could cause an integer overflow in the pagination logic, crashing the server before the response window is bounded. Affected versions are before 2.14.3 and before 2.12.12; fixed releases are 2.14.3 and 2...

CVE-2026-58210 NATS Server: MQTT partial CONNECT packets can exhaust pre-auth memory

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, an unauthenticated MQTT client could cause the server to retain large incomplete MQTT CONNECT packets before authentication completed, consuming server memory while the...

CVE-2026-58210

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, an unauthenticated MQTT client could cause the server to retain large incomplete MQTT CONNECT packets before authentication completed, consuming server memory while the...

CVE-2026-58210 NATS Server: MQTT partial CONNECT packets can exhaust pre-auth memory

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, an unauthenticated MQTT client could cause the server to retain large incomplete MQTT CONNECT packets before authentication completed, consuming server memory while the...