Advisory

Defending Against an Active Threat to Siemens S7 Series PLCs

Source

US-CERT Alerts

Published

2026-08-14

<h2><strong>Executive summary</strong></h2> <p><em><strong>Note:</strong> This advisory relates to an active threat to Siemens S7 Series programmable logic controllers (PLCs). However, ongoing PLC targeting activity is broader than Siemens PLCs. All PLC owners and operators should apply relevant mitigations to reduce the risk to their devices and systems. The Siemens-specific content in this advisory should be understood and applied as one subset of the wider threat landscape.</em></p> <p><strong>Top Mitigations</strong></p> <ul type="disc"> <li><strong>Inventory&nbsp;</strong>all Siemens S7 S