CVE-2024-42651Public exploitNetwork attack vector

Broker crash via retained-message pointer reuse

Published Jul 29, 2025 · Updated Jul 29, 2025

Heap use-after-free in NanoMQ 0.17.9 allows remote attackers to crash the broker with a crafted multi-topic SUBSCRIBE message. During retained-message matching in sub_Ctx_handle, NanoMQ queues and frees a matching message without clearing its pointer, then reuses the dangling pointer when a later topic matches under rh=1 handling. Network access to the MQTT listener is sufficient; the documented consequence is broker memory corruption and a service crash.

CVSS severity7.5
High
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap use-after-free in NanoMQ 0.17.9 allows remote attackers to crash the broker with a crafted multi-topic SUBSCRIBE message. During retained-message matching in sub_Ctx_handle, NanoMQ queues and frees a matching message without clearing its pointer, then reuses the dangling pointer when a later topic matches under rh=1 handling. Network access to the MQTT listener is sufficient; the documented consequence is broker memory corruption and a service crash.

The record

CVE
CVE-2024-42651
Published
Jul 29, 2025
Updated
Jul 29, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 29, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 29, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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