NanoMQ has Use-After-Free of malformed bridging message_CVE-2025-66023

6.9 / 10

MEDIUM

CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H

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.

Basic Information

ID CVE-2025-66023

Source GitHub_M

Published Jan 1, 2026 at 15:11

Affected Product

Vendor nanomq

Product nanomq

Version < 0.24.5

Affected Versions nanomq nanomq < 0.24.5

CWE Classification

CWE-416

References

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    "published": "2026-01-01T15:11:46.028Z",
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