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Denial of Service in Rockwell Automation FLEX I/O 1794-AENTR/1794-AENTRXT EtherNet/IP Adapters

IdentifiersCVE-2026-0646CWE-401· Missing Release of Memory after…

CVE-2026-0646 is a denial-of-service vulnerability affecting Rockwell Automation FLEX I/O dual-port EtherNet/IP adapters, specifically models 1794-AENTR and 1794-AENTRXT running affected firmware such as version 2.012. The issue is caused by improper memory handling of CIP protocol requests, and the available references map it to CWE-401 (missing release of memory after effective lifetime). A remote attacker can send crafted CIP requests to the adapter and trigger a fault condition in the device. When triggered, the adapter loses connection to its associated I/O modules and does not automatically recover, requiring a manual reset to restore operation.

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ANALYST BRIEF

Impact, mitigation & remediation

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Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation causes a loss of availability of the affected adapter. The device can fault and sever communication with attached I/O modules, disrupting EtherNet/IP-connected industrial control operations. Because recovery requires a manual reset, the issue can create sustained operational interruption and potential process downtime until personnel intervene.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, restrict access to EtherNet/IP/CIP services on affected adapters to trusted hosts and trusted network segments only. Minimize exposure of control devices, ensure they are not reachable from the internet, place control networks behind firewalls, isolate them from business networks, and use secured remote access paths such as updated VPNs. Perform impact analysis and risk assessment before applying defensive changes in production OT environments.

Remediation

Patch, then assume compromise.

Rockwell Automation fixed this vulnerability in firmware version 2.013. Affected organizations should upgrade 1794-AENTR and 1794-AENTRXT adapters from vulnerable firmware, including version 2.012, to version 2.013 or later as provided by the vendor. Validate firmware compatibility and perform appropriate OT change-control and impact assessment before deployment.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

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VendorProductType
Rockwell Automation1794-Aentrhardware
Rockwell AutomationFlex I.O. Ethernet.Ip Adaptershardware

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Threat actor evidence

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Detection signatures

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Vendor-by-vendor mapping

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Social activity3

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