CVE-2026-36590

NanoMQ before version 0.24.4 has a buffer overflow vulnerability when PUBLISH packets trigger both shared and vanilla subscriptions. This is fixed in version 0.24.4.

In nanomq versions 0.24.11 and earlier, a NULL pointer dereference in `properties_parse()` allows an authenticated attacker to crash the NanoMQ broker by sending a POST request to `/api/v4/mqtt/publish` with `user_properties` as a JSON array instead of a JSON object. The crash occurs because `strlen()` is called on a NULL `item->string` pointer when iterating over array elements.

In nanomq versions 0.24.11 and earlier, a NULL pointer dereference in nni_mqttv5_msg_decode_connect allows a malicious MQTT broker to crash any connecting NanoMQ MQTTv5 client (including bridge mode) with a single packet, causing remote denial of service via SIGSEGV. The issue occurs because the code uses variable 'prop' instead of 'will_prop' when iterating over CONNECT properties.

NanoMQ contains a protocol-semantics flaw in its MQTT v5 SUBSCRIBE handling. If a subscription entry is missing the final 1-byte Subscription Options field, the broker may accept the malformed packet and install the subscription. Under specific conditions, the same parser flaw also causes a 1-byte out-of-bounds read detected by ASAN as a heap-buffer-overflow.

In NanoMQ MQTT Broker version 0.24.8 and earlier, quic_stream_recv can dereference a null substream pointer when a substream is in reopen state. The code finishes the AIO with error but does not return before locking c->mtx, potentially leading to crashes or other issues.

NanoMQ MQTT Broker before version 0.24.14 has a type confusion vulnerability during dialer close. This leads to incorrect object interpretation and may cause hang or crash.

NULL pointer dereference vulnerability in NanoMQ MQTT Broker versions 0.24.10 and below during high-concurrency reconnect traffic. Causes broker crash (DoS) without authentication. Fixed in version 0.24.11.

NanoMQ before version 0.24.10 has an out-of-bounds read vulnerability in the hook_work_cb() function in webhook_inproc.c. The cJSON_Parse function reads data from a buffer without a guaranteed null terminator, potentially accessing memory beyond the allocated buffer.

NanoMQ version 0.16.5 is vulnerable to heap-use-after-free in the nano_ctx_send function of nmq_mqtt.c.

NanoMQ version 0.17.5 has a heap-based buffer over-read in the conn_handler function of mqtt_parser.c when processing malformed messages.