CVE-2025-66023

NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. Versions prior to 0.24.5 have a Heap-Use-After-Free (UAF) vulnerability within the MQTT bridge client component (implemented via the underlying NanoNNG library). The vulnerability is triggered when NanoMQ acts as a bridge connecting to a remote MQTT broker. A malicious remote broker can trigger a crash (Denial of Service) or potential memory corruption by accepting the connection and immediately sending a malformed packet sequence. Version 0.34.5 contains a patch. The patch enforces stricter protocol adherence in the MQTT client SDK embedded in NanoMQ. Specifically, it ensures that CONNACK is always the first packet processed in the line. This prevents the state confusion that led to the Heap-Use-After-Free (UAF) when a malicious server sent a malformed packet sequence immediately after connection establishment. As a workaround, validate the remote broker before bridging.
Configurations

Configuration 1 (hide)

cpe:2.3:a:emqx:nanomq:*:*:*:*:*:*:*:*

History

18 Feb 2026, 16:34

Type Values Removed Values Added
CPE cpe:2.3:a:emqx:nanomq:*:*:*:*:*:*:*:*
First Time Emqx
Emqx nanomq
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 4.9
References () https://github.com/nanomq/NanoNNG/pull/1365 - () https://github.com/nanomq/NanoNNG/pull/1365 - Issue Tracking, Patch
References () https://github.com/nanomq/nanomq/issues/2145 - () https://github.com/nanomq/nanomq/issues/2145 - Issue Tracking
References () https://github.com/nanomq/nanomq/security/advisories/GHSA-24f7-q5hh-27hf - () https://github.com/nanomq/nanomq/security/advisories/GHSA-24f7-q5hh-27hf - Vendor Advisory

01 Jan 2026, 15:15

Type Values Removed Values Added
New CVE

Information

Published : 2026-01-01 15:15

Updated : 2026-02-18 16:34


NVD link : CVE-2025-66023

Mitre link : CVE-2025-66023

CVE.ORG link : CVE-2025-66023


JSON object : View

Products Affected

emqx

  • nanomq
CWE
CWE-416

Use After Free