nanomq: Heap-Buffer-Overflow in webhook_inproc.c via cJSON_Parse OOB Read
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA nanomq (nanomq) Fixed in 0.24.10
Timeline
- 2026-10-02 Threatist record created from CVE-2026-34608
References
More Nanomq vulnerabilities
- TI-2026-24672 NanoMQ has Heap Buffer Overflow in URI Parameter Parsing CVSS 4.0HIGH 7.7
- TI-2024-28570 An access control issue in NanoMQ v0.21.10 allows attackers to bypass security… CVSS 3.1HIGH 8.8
- TI-2026-27853 An issue in EMQ NanoMQ v.0.24.9 allows a remote attacker to cause a denial of service via… CVSS 3.1HIGH 7.5
- TI-2026-17589 MQTT v5 Variable Byte Integer parsing out-of-bounds: get_var_integer() CVSS 3.1HIGH 7.5
- TI-2024-20452 Null Pointer Dereference vulnerability in topic_filtern function in mqtt_parser.c in… CVSS 3.1HIGH 7.5
- TI-2023-17307 NanoMQ 0.16.5 is vulnerable to heap-use-after-free in the nano_ctx_send function of nmq_mqtt.c. CVSS 3.1HIGH 7.5
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences