CVE-2026-25627 in NanoMQ MQTT Broker

Summary

NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. Prior to version 0.24.8, NanoMQ’s MQTT-over-WebSocket transport can be crashed by sending an MQTT packet with a deliberately large Remaining Length in the fixed header while providing a much shorter actual payload. The code path copies Remaining Length bytes without verifying that the current receive buffer contains that many bytes, resulting in an out-of-bounds read (ASAN reports OOB / crash). This is remotely triggerable over the WebSocket listener. This issue has been patched in version 0.24.8.

Responsible

GitHub_M

Reservation

02/04/2026

Disclosure

03/31/2026

Entries

VulDB provides additional information and datapoints for this CVE:

ID	Vulnerability	CWE	Exp	Cou	CVE
354268	NanoMQ MQTT Broker MQTT Packet out-of-bounds	125	Not defined	Official fix	CVE-2026-25627