Rockwell FLEX 5000 EtherNet/IP Adapter DoS Vulnerability (CVE-2026-12659)

Vulnerability Overview Vulnerability Name: Flex 5000® Adapter - Denial of Service Severity: High CVE ID: CVE-2026-12659 Published Date: July 14, 2026 Last Updated Date: July 14, 2026 Revision Number: 1.0 Known Exploited Vulnerability (KEV): No Fixed: Yes Workarounds: None Affected Products Affected Products: FLEX 5000 EtherNet/IP Adapters Impact Description: A denial-of-service security vulnerability affects the product. The security issue involves improper handling of crafted CIP packets during exception handling. A power cycle is required to restore associated I/O. CVSS 3.1 Base Score: 7.5/10 CVSS 4.0 Base Score: 8.7/10 CWE: CWE-455: Double Free Remediation Remediation Status: Fixed Workarounds: None Mitigations: Customers using the affected software who are unable to upgrade to the fixed version should employ security best practices. Additional Information Product Description: FLEX 5000 EtherNet/IP Adapters are high-performance distributed I/O adapters that connect FLEX 5000 I/O modules to an EtherNet/IP network, supporting advanced network topologies, including Device Level Ring (DLR), in industrial automation applications. Security Best Practices: Visit the Rockwell Automation security advisory page, subscribe to product security alerts, view the latest list of security advisories, report potential security issues, and learn more about our vulnerability policy. Contact Support Technical Support: For any questions regarding security issues, please contact TechConnect. Legal Disclaimer: Rockwell Automation does not guarantee the completeness, timeliness, or accuracy of the information. Footer Information Company Information: About, News & Events, Training, Partner Network, Insights, etc. Social Media: LinkedIn, Facebook, X, YouTube, RSS. The above is a summary of the key information regarding the vulnerability from the webpage screenshot.

Goal Reached Thanks to every supporter — we hit 100%!

Rockwell FLEX 5000 EtherNet/IP Adapter DoS Vulnerability (CVE-2026-12659)