CVE-2026-25627 PUBLISHED

nanomq: OOB Read / Crash (DoS) via Malformed MQTT Remaining Length over WebSocket

Assigner: GitHub_M
Reserved: 04.02.2026 Published: 30.03.2026 Updated: 30.03.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 6.5

Product Status

Vendor nanomq
Product nanomq
Versions
  • Version < 0.24.8 is affected

References

Problem Types

  • CWE-125: Out-of-bounds Read CWE