CVE-2026-32134Public exploitNetwork attack vector

Unauthenticated broker crash via reconnect session race

Published May 19, 2026 · Updated May 19, 2026

NULL pointer dereference in EMQ Technologies NanoMQ and NanoNNG before 0.24.11 allows remote attackers to crash the broker. During clean_start=0 session resumption, tcptran_pipe_peer iterates cpipe->subinfol after a reconnect race frees and nulls that list. Unauthenticated TCP clients must create high-concurrency client-ID collisions; successful triggering terminates the broker process without disclosing or modifying data.

CVSS severity5.9
Medium
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in EMQ Technologies NanoMQ and NanoNNG before 0.24.11 allows remote attackers to crash the broker. During clean_start=0 session resumption, tcptran_pipe_peer iterates cpipe->subinfol after a reconnect race frees and nulls that list. Unauthenticated TCP clients must create high-concurrency client-ID collisions; successful triggering terminates the broker process without disclosing or modifying data.

The record

CVE
CVE-2026-32134
Published
May 19, 2026
Updated
May 19, 2026
Vendor
EMQ Technologies
Product
NanoNNG
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 19, 2026CVE publishedPublication date reported by the CVE source.
  2. May 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.24.11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

EMQ Technologies · NanoNNGversion=< 0.24.11
EMQ Technologies · NanoMQversion=< 0.24.11

Published CVSS scores

5.9GitHub, Inc.CVSS:3.1/AV:N/AC:H/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-476NULL Pointer Dereference
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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