CVE-2025-66023

4.9 MEDIUM
Published: January 01, 2026 Modified: February 18, 2026
View on NVD

Description

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/nanomq/NanoNNG/pull/1365
Source: security-advisories@github.com
Issue Tracking Patch
https://github.com/nanomq/nanomq/issues/2145
Source: security-advisories@github.com
Issue Tracking
https://github.com/nanomq/nanomq/security/advisories/GHSA-24f7-q5hh-27hf
Source: security-advisories@github.com
Vendor Advisory

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
4.9 / 10.0
EPSS (Exploit Probability)
0.1%
16th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

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