Original Article Summary

View CSAF Summary Successful exploitation of this vulnerability could allow an attacker to cause a denial-of-service condition on the affected product. The following versions of Rockwell Automation Flex 5000 Adapter are affected: Flex 5000 Adapter 6.011 (CVE-2026-12659) CVSS Vendor Equipment Vulnerabilities v3 7.5 Rockwell Automation Rockwell Automation Flex 5000 Adapter Double Free Background Critical Infrastructure Sectors: Critical Manufacturing, Information Technology Countries/Areas Deployed: Worldwide Company Headquarters Location: United States Vulnerabilities Expand All + CVE-2026-12659 A denial-of-service security issue exists in the affected products. The security issue stems from improper handling of exceptional conditions when processing crafted CIP packets sent to the adapter. A power cycle is required to recover the module and associated I/O. View CVE Details Affected Products Rockwell Automation Flex 5000 Adapter Vendor: Rockwell Automation Product Version: Rockwell Automation Flex 5000 Adapter: 6.011 Product Status: known_affected Remediations Vendor fix Rockwell Automation recommends users to upgrade to the following: Flex 5000 Adapter version 6.012. Mitigation Customers using the affected software, who are not able to upgrade to one of the corrected versions, should use Rockwell Automation's security best practices (https://support.rockwellautomation.com/app/answers/answer_view/a_id/1085012/loc/en_US#__highlight). https://support.rockwellautomation.com/app/answers/answer_view/a_id/1085012/loc/en_US#__highlight Mitigation For more information, see Rockwell Automation Security Advisory SD1789 (https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1789.html). https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1789.html Relevant CWE: CWE-415 Double Free Metrics CVSS Version Base Score Base Severity Vector String 3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 4.0 8.7 HIGH 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 Acknowledgments Rockwell Automation reported this vulnerability to CISA Legal Notice and Terms of Use This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy). Recommended Practices CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolating them from business networks. 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. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. 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. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. 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. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. CISA also recommends users take the following measures to protect themselves from social engineering attacks: Do not click web links or open attachments in unsolicited email messages. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. Revision History Initial Release Date: 2026-07-16 Date Revision Summary 2026-07-16 1 Initial Republication of Rockwell Automation Security Advisory SD1789 Legal Notice and Terms of Use