CVE-2026-73863Public exploitNetwork attack vectorHinoki check available

Broker crash via reused property-length cursor

Published Sep 18, 2026 · Updated Sep 18, 2026

Out-of-bounds read in NanoMQ before 0.24.14 allows remote attackers to crash the broker via a crafted MQTT v5 SUBSCRIBE packet. nmq_subinfo_decode() reuses the outer Properties Length cursor for each subscription identifier, making get_var_integer() start at the wrong offset and read past the heap buffer. The broker must accept an MQTT v5 connection; no authentication or user interaction is required, and a successful trigger interrupts service.

CVSS severity7.0
High
EPSS probability0.35%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Out-of-bounds read in NanoMQ before 0.24.14 allows remote attackers to crash the broker via a crafted MQTT v5 SUBSCRIBE packet. nmq_subinfo_decode() reuses the outer Properties Length cursor for each subscription identifier, making get_var_integer() start at the wrong offset and read past the heap buffer. The broker must accept an MQTT v5 connection; no authentication or user interaction is required, and a successful trigger interrupts service.

The record

CVE
CVE-2026-73863
Published
Sep 18, 2026
Updated
Sep 18, 2026
Vendor
EMQ Technologies
Product
NanoMQ
Classifications
CWE-125, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 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=< 0.24.14

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

EMQ Technologies · NanoMQversion=< 0.24.14

Published CVSS scores

7.0GitHubCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA: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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
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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