CVE-2026-6564Public exploitNetwork attack vector

Authenticated client disconnection via Client ID reuse

Published Apr 19, 2026 · Updated Apr 19, 2026

Session handling in EMQ EMQX Enterprise 6.0 and 6.1.0 allows remote authenticated users to disconnect another MQTT client. A second connection using the target's Client ID replaces the existing broker session because the identifier is not bound to the authenticated username. The report requires valid MQTT credentials and knowledge or guessing of the target ID; EMQ disputes the CVE and calls the result required MQTT takeover behavior.

CVSS severity4.3
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Session handling in EMQ EMQX Enterprise 6.0 and 6.1.0 allows remote authenticated users to disconnect another MQTT client. A second connection using the target's Client ID replaces the existing broker session because the identifier is not bound to the authenticated username. The report requires valid MQTT credentials and knowledge or guessing of the target ID; EMQ disputes the CVE and calls the result required MQTT takeover behavior.

The record

CVE
CVE-2026-6564
Published
Apr 19, 2026
Updated
Apr 19, 2026
Vendor
EMQ
Product
EMQX Enterprise
Classifications
CWE-285, CWE-266, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

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

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=6.0
  2. Affected versionversion=6.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

EMQ · EMQX Enterpriseversion=6.0; version=6.1.0

Published CVSS scores

4.3VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
4.0VulDBAV:N/AC:L/Au:S/C:N/I:N/A:P
2.1VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

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.

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

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-285Improper Authorization
CWE-266Incorrect Privilege Assignment
T1499Endpoint Denial of Service

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo