Denial-of-Service Vulnerabilities in Rockwell Automation Logix Platforms

On September 1, 2026, CISA published advisories regarding denial-of-service vulnerabilities in Rockwell Automation's Logix platforms, specifically affecting ControlLogix and CompactLogix systems. The vulnerabilities, identified as CVE-2026-9637 and CVE-2021-42260, can be triggered by corrupt crafted data or improper input length validation during message processing. Affected versions include ControlLogix 5580 and CompactLogix 5380 with firmware versions below 34.015 and 35.014, respectively. The vulnerabilities could lead to major nonrecoverable faults (MNRF), necessitating either a program download or a power cycle for recovery. Rockwell Automation recommends users upgrade to the latest firmware versions to mitigate the risks. CISA advises implementing security best practices to minimize network exposure and enhance system security. The vulnerabilities are applicable worldwide and impact critical manufacturing sectors.

Key Points: • CVE-2026-9637 and CVE-2021-42260 affect multiple Rockwell Automation Logix platforms. • Denial-of-service vulnerabilities can cause major nonrecoverable faults (MNRF). • Users are urged to upgrade firmware to versions 34.015 and later for mitigation.