CVE-2026-12659Network attack vector

Unauthenticated service halt via CIP packet double free

Published Jul 14, 2026 · Updated Jul 14, 2026

Denial of service in Rockwell Automation FLEX 5000 EtherNet/IP Adapter 6.011 allows remote attackers to halt it via crafted CIP packets. The firmware mishandles an exceptional condition during CIP packet processing and double-frees memory, leaving the module and associated I/O in a nonrecoverable fault state. Network access is sufficient, and the outage persists until the adapter and associated I/O are power-cycled.

CVSS severity8.7
High
EPSS probability0.43%
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 Rockwell Automation FLEX 5000 EtherNet/IP Adapter 6.011 allows remote attackers to halt it via crafted CIP packets. The firmware mishandles an exceptional condition during CIP packet processing and double-frees memory, leaving the module and associated I/O in a nonrecoverable fault state. Network access is sufficient, and the outage persists until the adapter and associated I/O are power-cycled.

The record

CVE
CVE-2026-12659
Published
Jul 14, 2026
Updated
Jul 14, 2026
Vendor
Rockwell Automation
Product
FLEX 5000 EtherNet/IP Adapter
Classifications
CWE-415, T0814
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 14, 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=version 6.011

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Rockwell Automation · FLEX 5000 EtherNet/IP Adapterversion=version 6.011

Published CVSS scores

7.5Rockwell AutomationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7Rockwell AutomationCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-415Double Free
T0814Denial of Service

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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