---
id: CVE-2026-44639
title: NanoMQ is an MQTT broker
summary: >-
  NanoMQ is an MQTT broker. Prior to 0.24.14, NanoMQ's MQTT v5 property decoder
  in nng/src/supplemental/mqtt/mqtt_codec.c uses property_append() to walk the
  entire linked list for each property added by decode_buf_properties(). A
  remote un…
severity: low
cvss: 3.7
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-407
vendor: nanomq
product: nanomq
affected:
  - nanomq < 0.24.14
published: '2026-09-18'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T18:17:06.990'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-44639'
references:
  - url: >-
      https://github.com/nanomq/NanoNNG/commit/91bd4c7f45f945a3f5f0e37c459157dc7c277a07
    label: security-advisories@github.com
  - url: 'https://github.com/nanomq/NanoNNG/pull/1508'
    label: security-advisories@github.com
  - url: 'https://github.com/nanomq/nanomq/releases/tag/0.24.14'
    label: security-advisories@github.com
  - url: 'https://github.com/nanomq/nanomq/security/advisories/GHSA-6mwg-445v-2qrv'
    label: security-advisories@github.com
  - url: 'https://github.com/nanomq/nanomq/security/advisories/GHSA-6mwg-445v-2qrv'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-18T17:19:13.578066Z'
ingestedAt: '2026-09-18T16:45:41.411Z'
epss: 0.00443
epssPercentile: 0.35889
---

## Overview

NanoMQ is an MQTT broker. Prior to 0.24.14, NanoMQ's MQTT v5 property decoder in nng/src/supplemental/mqtt/mqtt_codec.c uses property_append() to walk the entire linked list for each property added by decode_buf_properties(). A remote unauthenticated client can supply a PUBLISH or SUBSCRIBE packet containing many User Properties, causing O(N²) linked-list insertion and CPU work that makes the broker unresponsive; repeated packets can sustain the denial of service. This issue is fixed in version 0.24.14.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.