Rockwell Automation Addresses Critical DoS Vulnerabilities in RSLinx Classic

Rockwell Automation has patched over a dozen vulnerabilities, including four critical denial-of-service (DoS) issues in RSLinx Classic software, affecting versions up to 4.50. Exploitation of these vulnerabilities can cause the RSLinx Classic service to crash, requiring a restart for recovery. The vulnerabilities are identified as CVE-2026-9621, CVE-2026-9622, CVE-2026-9624, and CVE-2026-9625. Users unable to upgrade are advised to follow Rockwell Automation's security best practices. Additionally, a high-severity DoS flaw in ControlLogix and CompactLogix controllers was flagged, although its exploitation status is unclear. The vulnerabilities were disclosed in advisories published on September 1, 2026, by both CISA and Rockwell Automation. The patches are now available for affected users worldwide.

Key Points: • Four critical DoS vulnerabilities in RSLinx Classic patched by Rockwell Automation. • Affected versions include RSLinx Classic up to 4.50; users should upgrade to 4.60. • CISA and Rockwell Automation published advisories on September 1, 2026.