# CVE-2026-47276: NanoMQ NULL pointer dereference in REST API properties_parse

Source: https://junglewise.ai/threats/cve-2026-47276-nanomq-null-pointer-dereference-in-rest-api-properties-parse  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-20. Updated: 2026-07-20  
License: CC BY 4.0 with a link back

CVE-2026-47276 · Severity: medium · CVSS 6.5 · Published 2026-07-20

NanoMQ is a lightweight message broker used to facilitate communication between Internet of Things (IoT) devices. A vulnerability in its management interface allows an authenticated user to crash the broker by sending a specially formatted request. If exploited, this would cause a complete service outage, disconnecting all connected devices and disrupting real-time data operations until the service is manually restarted.

Technologies: [EMQ NanoMQ](https://junglewise.ai/threats/technologies/nanomq). Vendors: [EMQ](https://junglewise.ai/threats/vendors/emq).

## Quick answers

**Is CVE-2026-47276 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-47276 being exploited in the wild.

**How severe is CVE-2026-47276?** Medium severity, with a CVSS score of 6.5, published 20 July 2026.

**Which products and versions are affected?** EMQ NanoMQ <= 0.24.11.

**Is there a fix for CVE-2026-47276?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-47276 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-47276?** Check whether you run EMQ NanoMQ at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A NULL pointer dereference exists in the `properties_parse()` function within `rest_api.c` of NanoMQ. The vulnerability is triggered when the REST API endpoint `/api/v4/mqtt/publish` receives a JSON payload where the `user_properties` field is formatted as a JSON array rather than the expected JSON object. The code uses `cJSON_ArrayForEach` to iterate over the elements but fails to validate the JSON type; since array elements in cJSON do not have key names, `item->string` is NULL. A subsequent call to `strlen(item->string)` results in a segmentation fault (SIGSEGV), crashing the broker process. This attack requires network access and valid HTTP Basic Authentication credentials. The issue is resolved in version 0.24.14.

## Affected products

- NanoMQ NanoMQ <= 0.24.11

## Timeline

- 2026-07-08: advisory: GitHub Security Advisory published
- 2026-07-20: disclosed: NVD publication date

## References

- [https://github.com/nanomq/nanomq/security/advisories/GHSA-qq2v-xvxg-3hvf](https://github.com/nanomq/nanomq/security/advisories/GHSA-qq2v-xvxg-3hvf)

## Related threats

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