CVE-2026-34608
MediumCVSS 4.9Exploitation Probability (EPSS)
Low risk28th percentile - higher than 28% of all known CVEs
Summary
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.
Risk Assessment
An attacker can cause sensitive memory data leakage or server crash by sending a specially crafted JSON payload with a power-of-two length >=1024.
Recommendation
Update NanoMQ to version 0.24.10 or later, which includes the fix.
Other vulnerabilities in NanoMQ
See all- CVE-2025-59947Critical
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.
- CVE-2026-73863High
In NanoMQ MQTT broker prior to 0.24.14, the nmq_subinfo_decode() function reuses the length variable from the outer Properties Length while parsing each subscription identifier. A remote client can send a SUBSCRIBE packet with a multi-byte Properties Length and repeated subscription identifiers, causing a read beyond the heap message buffer. The issue is fixed in version 0.24.14.
- CVE-2026-61633Low
A vulnerability in NanoMQ before 0.24.14 in the client function nni_mqtt_msg_decode_unsubscribe() fails to handle a failed read while counting topics in a malformed UNSUBSCRIBE packet. This can hang a connecting MQTT 3.1.1 client, consume CPU and memory, and repeatedly deny service when auto-reconnect is enabled.
- CVE-2026-44639Low
NanoMQ, an MQTT broker, prior to 0.24.14 has an MQTT v5 property decoder that walks the entire linked list for each property added, resulting in O(N²) complexity. A remote unauthenticated client can send a PUBLISH or SUBSCRIBE packet with many User Properties, causing excessive CPU usage and broker unresponsiveness.
- CVE-2026-47276Medium
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.
- CVE-2026-47275Low
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.
- CVE-2026-35217Medium
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.
- CVE-2026-36590High
A vulnerability in NanoMQ version 0.24.9 allows a remote attacker to cause a denial of service (DoS) via the nni_qos_db_set function in the broker_tcp.c component.
- CVE-2026-45151Low
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.
- CVE-2026-44640Medium
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.
Original NVD description (English source)
NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. Prior to version 0.24.10, in NanoMQ's webhook_inproc.c, the hook_work_cb() function processes nng messages by parsing the message body with cJSON_Parse(body). The body is obtained from nng_msg_body(msg), which is a binary buffer without a guaranteed null terminator. This leads to an out-of-bounds read (OOB read) as cJSON_Parse reads until it finds a \0, potentially accessing memory beyond the allocated buffer (e.g., nng_msg metadata or adjacent heap/stack). The issue is often masked by nng's allocation padding (extra 32 bytes of zeros for non-power-of-two sizes <1024 or non-aligned). The overflow is reliably triggered when the JSON payload length is a power-of-two >=1024 (no padding added). This issue has been patched in version 0.24.10.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS