CVE-2026-58214

CVE-2026-58214 – NATS Server (MQTT subscribe ACL bypass) Prior to version 2.14.3 and 2.12.12, an authenticated MQTT client could subscribe to the internal $MQTT.deliver.pubrel subject family, bypassing configured subscribe permissions and exposing MQTT QoS2 protocol metadata for sessions in the a...

CVE-2026-58209

NATS Server before versions 2.14.3 and 2.12.12 could deliver MQTT retained messages and QoS1+ durable replays to subscribers whose topics matched a deny rule, because delivery paths did not consistently re-check the original topic before sending MQTT PUBLISH. This issue is fixed in 2.14.3 and 2.1...

CVE-2026-58254

NATS Server (affected components: leafnode message trace destination checks) could allow a leafnode operator to send trace events to subjects that should be disallowed and use trace-only behavior to interfere with delivery/storage. Root cause: checks were applied to ordinary client connections bu...

CVE-2026-58208

CVE-2026-58208 affects NATS Server. 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 WebSocket access to reach an uninitialized MQTT state and crash the server process. This iss...

CVE-2026-58213

NATS Server (nats-server) before versions 2.14.1 and 2.12.9 is vulnerable: an MQTT client can include protocol control characters in subscription filters, which are later forwarded as NATS protocol data to route or leafnode connections. This corrupts the forwarded protocol stream and allows injec...

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-2026-58211

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-2026-58210

CVE-2026-58210 affects NATS Server prior to versions 2.14.3 and 2.12.12. An unauthenticated MQTT client could cause the server to retain large incomplete MQTT CONNECT packets before authentication completes, exhausting memory due to the parser waiting for the advertised MQTT packet length. The is...