Rockwell Automation FLEX I/O EtherNet/IP Adapters
Summary
<p><a href="https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-167-05.json"><strong>View CSAF</strong></a></p> <h2>Summary</h2> <p><strong>Successful exploitation of these vulnerabilities could allow an attacker to gain unauthorized access, account takeover, and cause loss of availability.</strong></p> <p>The following versions of Rockwell Automation FLEX I/O EtherNet/IP Adapters are affected:</p> <ul> <li>1794-AENTR V2.012 (CVE-2026-0646, CVE-2026-0647)</li> <li>1794-AENTRXT V2.012 (CVE-2026-0646, CVE-2026-0647)</li> </ul> <div class="csaf-table"> <table class="tablesaw tablesaw-stack"> <thead> <tr> <th>CVSS</th> <th>Vendor</th> <th>Equipment</th> <th>Vulnerabilities</th> </tr> </thead> <tbody> <tr> <td>v3 9.4</td> <td>Rockwell Automation</td> <td>Rockwell Automation FLEX I/O EtherNet/IP Adapters</td> <td>Missing Release of Memory after Effective Lifetime, Missing Authentication for Critical Function</td> </tr> </tbody> </table> </div> <h3>Background</h3> <ul> <li><strong>Critical Infrastructure Sectors: </strong>Critical Manufacturing</li> <li><strong>Countries/Areas Deployed: </strong>Worldwide</li> <li><strong>Company Headquarters Location: </strong>United States</li> </ul> <hr /> <h2>Vulnerabilities</h2> <div class="csaf-accordion"> <p><a class="csaf-accordion-toggle-all" href="https://www.cisa.gov/">Expand All +</a></p> <div class="csaf-accordion-item"> <h3><a class="csaf-accordion-toggle" href="https://www.cisa.gov/">CVE-2026-0646</a></h3> <div class="csaf-accordion-content"> <p>A denial-of-service security issue exists within the 1794-AENTR adapter due to improper memory handling of CIP protocol requests. This vulnerability can result in the adapter faulting and losing connection to its associated I/O modules, requiring a manual reset to recover.</p> <p><a href="https://www.cve.org/CVERecord?id=CVE-2026-0646">View CVE Details</a></p> <hr /> <h4>Affected Products</h4> <h5>Rockwell Automation FLEX I/O EtherNet/IP Adapters</h5> <div class="ics-vendor-version-status"> <div class="ics-vendor"><strong>Vendor:</strong><br />Rockwell Automation</div> <div class="ics-version"><strong>Product Version:</strong><br />Rockwell Automation 1794-AENTR: V2.012, Rockwell Automation 1794-AENTRXT: V2.012</div> <div class="ics-status"><strong>Product Status:</strong><br />known_affected</div> </div> <div class="ics-remediations"> <h6>Remediations</h6> <p><strong>Mitigation</strong><br />Rockwell Automation recommends users update to 2.013 to resolve these vulnerabilities.</p> <p><strong>Mitigation</strong><br />For more information, please visit Rockwell Automation's SD1775 https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1775.html<br /><a href="https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1775.html">https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1775.html</a></p> </div> <p><strong>Relevant CWE:</strong> <a href="https://cwe.mitre.org/data/definitions/401.html">CWE-401 Missing Release of Memory after Effective Lifetime</a></p> <hr /> <h4>Metrics</h4> <div class="csaf-table csaf-metrics-table"> <table class="tablesaw tablesaw-stack"> <thead> <tr> <th>CVSS Version</th> <th>Base Score</th> <th>Base Severity</th> <th>Vector String</th> </tr> </thead> <tbody> <tr> <td>3.1</td> <td>7.5</td> <td>HIGH</td> <td><a href="https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H">CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H</a></td> </tr> <tr> <td>4.0</td> <td>8.7</td> <td>HIGH</td> <td><a href="https://www.first.org/cvss/calculator/4.0#CVSS: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:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N</a></td> </tr> </tbody> </table> </div> </div> </div> <div class="csaf-accordion-item"> <h3><a class="csaf-accordion-toggle" href="https://www.cisa.gov/">CVE-2026-0647</a></h3> <div class="csaf-accordion-content"> <p>An improper authentication security issue exists within the 1794-AENTR adapter's embedded web server. The vulnerability allows an unauthenticated attacker to change the device's web interface password by sending a crafted HTTP GET request to a specific endpoint, without any prior authentication being required. If exploited, this could lead to unauthorized access, account takeover, and loss of the device's embedded web server's availability.</p> <p><a href="https://www.cve.org/CVERecord?id=CVE-2026-0647">View CVE Details</a></p> <hr /> <h4>Affected Products</h4> <h5>Rockwell Automation FLEX I/O EtherNet/IP Adapters</h5> <div class="ics-vendor-version-status"> <div class="ics-vendor"><strong>Vendor:</strong><br />Rockwell Automation</div> <div class="ics-version"><strong>Product Version:</strong><br />Rockwell Automation 1794-AENTR: V2.012, Rockwell Automation 1794-AENTRXT: V2.012</div> <div class="ics-status"><strong>Product Status:</strong><br />known_affected</div> </div> <div class="ics-remediations"> <h6>Remediations</h6> <p><strong>Mitigation</strong><br />Rockwell Automation recommends users update to 2.013 to resolve these vulnerabilities.</p> <p><strong>Mitigation</strong><br />For more information, please visit Rockwell Automation's SD1775 https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1775.html<br /><a href="https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1775.html">https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1775.html</a></p> </div> <p><strong>Relevant CWE:</strong> <a href="https://cwe.mitre.org/data/definitions/306.html">CWE-306 Missing Authentication for Critical Function</a></p> <hr /> <h4>Metrics</h4> <div class="csaf-table csaf-metrics-table"> <table class="tablesaw tablesaw-stack"> <thead> <tr> <th>CVSS Version</th> <th>Base Score</th> <th>Base Severity</th> <th>Vector String</th> </tr> </thead> <tbody> <tr> <td>3.1</td> <td>9.4</td> <td>CRITICAL</td> <td><a href="https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H">CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H</a></td> </tr> <tr> <td>4.0</td> <td>8.8</td> <td>HIGH</td> <td><a href="https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N">CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N</a></td> </tr> </tbody> </table> </div> </div> </div> </div> <hr /> <h2>Acknowledgments</h2> <ul> <li>Rockwell Automation reported these vulnerabilities to CISA</li> </ul> <hr /> <h2>Legal Notice and Terms of Use</h2> <p>This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy).</p> <hr /> <h2>Recommended Practices</h2> <p>CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities.</p> <p>Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.</p> <p>Locate control system networks and remote devices behind firewalls and isolating them from business networks.</p> <p>When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices.</p> <p>CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.</p> <p>CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.</p> <p>CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.</p> <p>Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.</p> <p>Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.</p> <p>CISA also recommends users take the following measures to protect themselves from social engineering attacks:</p> <p>Do not click web links or open attachments in unsolicited email messages.</p> <p>Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.</p> <p>Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.</p> <p>No known public exploitation specifically targeting these vulnerabilities has been reported to CISA at this time.</p> <hr /> <h2>Revision History</h2> <ul> <li><strong>Initial Release Date: </strong>2026-06-16</li> </ul> <table class="tablesaw tablesaw-stack"> <thead> <tr> <th>Date</th> <th>Revision</th> <th>Summary</th> </tr> </thead> <tbody> <tr> <td>2026-06-16</td> <td>1</td> <td>Initial Republication of Rockwell Automation Security Advisory SD1775</td> </tr> </tbody> </table> <hr /> <h2>Legal Notice and Terms of Use</h2>