CISA Issues Its Most Actionable OT Cybersecurity Advisory Yet

When it comes to securing industrial systems, security advisories from government agencies have often stopped short of being truly useful. They have raised awareness, but rarely handed operators a clear roadmap for action. That changed recently with the release of a sweeping guidance from the Cybersecurity and Infrastructure Security Agency (CISA) and its global partners, focused on building operational technology (OT) asset inventories and taxonomies as the foundation of resilient critical infrastructure defense.

Why Asset Inventories Matter

The advisory highlights a deceptively simple problem: many operators don’t know exactly what assets sit inside their industrial environments. Without a comprehensive inventory, defenders cannot effectively patch vulnerabilities, model risks, or plan incident responses. The new guidance outlines a structured process for owners and operators to identify, categorize, and maintain records of every OT system, from legacy controllers to modern industrial IoT devices.

By framing inventory management around a standardized taxonomy, the advisory pushes organizations to go beyond lists and spreadsheets. Instead, assets are grouped by criticality, function, and interdependencies, enabling defenders to prioritize protections and simulate how cyber incidents could cascade across physical operations.

Beyond Awareness to Implementation

That emphasis on action resonated with industry experts. Sean Tufts, Field CTO at Claroty, said:

“This is the most actionable advisory I’ve seen from CISA to date. Over the past five years, global governments have published documentation for critical infrastructure that was helpful for raising awareness but difficult to implement practically. While these documents succeeded in drawing attention to OT security challenges, they often lacked clear pathways for organizations to enact meaningful change. This new advisory represents a significant improvement because it’s genuinely actionable. It successfully integrates three key stakeholders; OT operators, the current capabilities of cybersecurity software providers (CPS PP), and established industry standards. Rather than simply recommending another process improvement or tool installation, this combination creates a comprehensive program framework. Companies scared to start an OT program can use this as a guide.”

A Global Effort

The guide was authored not just by CISA but also by the NSA, FBI, EPA, and cyber agencies from Australia, Canada, Germany, the Netherlands, and New Zealand. It reflects lessons from collaborative sessions with utilities, energy producers, and water operators—sectors that remain prime targets for ransomware crews and state-backed attackers.

Each sector receives conceptual taxonomies tailored to its environment: oil and gas, electricity, and water and wastewater. These are not one-size-fits-all directives, but frameworks meant to help operators develop their own classification systems aligned with international standards like ISA/IEC 62443.

Raising the Bar

The timing is critical. OT networks are more interconnected than ever, bridging legacy equipment with modern IT systems. That convergence has widened attack surfaces, enabling cybercriminals to pivot from business networks into physical processes. The guidance directly addresses this risk, urging organizations to integrate asset inventories with vulnerability management, continuous monitoring, and incident response planning.

For a space long dominated by “awareness” campaigns, the release marks a clear shift toward prescriptive cybersecurity. Whether operators embrace it may determine how well critical infrastructure withstands the next wave of cyberattacks.