CVE-2025-8531Network attack vector

Control-program stoppage via crafted length-inconsistent packets

Published Sep 19, 2025 · Updated Sep 19, 2025

Denial of service in Mitsubishi Electric MELSEC-Q Series serial numbers 24082 through 27081 allows remote attackers to stop control programs. With user authentication enabled, crafted packets trigger an integer underflow in length handling, stopping Ethernet communication and control programs until reset. The function is normally disabled and is enabled by default only for qualifying GX Works2 configurations.

CVSS severity6.8
Medium
EPSS probability1.02%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Mitsubishi Electric MELSEC-Q Series serial numbers 24082 through 27081 allows remote attackers to stop control programs. With user authentication enabled, crafted packets trigger an integer underflow in length handling, stopping Ethernet communication and control programs until reset. The function is normally disabled and is enabled by default only for qualifying GX Works2 configurations.

The record

CVE
CVE-2025-8531
Published
Sep 19, 2025
Updated
Sep 19, 2025
Vendor
Mitsubishi Electric Corporation
Product
MELSEC-Q Series Q04UDPVCPU
Classifications
CWE-130, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 19, 2025Record 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=The first 5 digits of serial No. "24082" to "27081"

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mitsubishi Electric Corporation · MELSEC-Q Series Q04UDPVCPUversion=The first 5 digits of serial No. "24082" to "27081"
Mitsubishi Electric Corporation · MELSEC-Q Series Q26UDVCPUversion=The first 5 digits of serial No. "24082" to "27081"
Mitsubishi Electric Corporation · MELSEC-Q Series Q13UDVCPUversion=The first 5 digits of serial No. "24082" to "27081"
Mitsubishi Electric Corporation · MELSEC-Q Series Q06UDVCPUversion=The first 5 digits of serial No. "24082" to "27081"
Mitsubishi Electric Corporation · MELSEC-Q Series Q03UDVCPUversion=The first 5 digits of serial No. "24082" to "27081"
Mitsubishi Electric Corporation · MELSEC-Q Series Q13UDPVCPUversion=The first 5 digits of serial No. "24082" to "27081"
Mitsubishi Electric Corporation · MELSEC-Q Series Q04UDVCPUversion=The first 5 digits of serial No. "24082" to "27081"
Mitsubishi Electric Corporation · MELSEC-Q Series Q06UDPVCPUversion=The first 5 digits of serial No. "24082" to "27081"
Mitsubishi Electric Corporation · MELSEC-Q Series Q26UDPVCPUversion=The first 5 digits of serial No. "24082" to "27081"

Published CVSS scores

6.8Mitsubishi Electric CorporationCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/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 exploitUnconfirmed

Weakness, pattern, technique

CWE-130Improper Handling of Length Parameter Inconsistency
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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