TL;DR Siemens disclosed eight Siemens S7-1500 vulnerabilities in the PLC web server on October 13, 2026. Three of them rate critical at CVSS 4.0 score 9.4. No fix exists yet, so Siemens urges customers to apply mitigations now. Why It Matters SIMATIC S7-1500 controllers run production lines across many sectors. Siemens says these CPUs serve "manufacturing, food and beverages, and chemical industries worldwide." A compromised controller session could therefore affect physical processes, not just data.