Four OT Security Priorities for 2026

2025 made one truth uncomfortably clear: the biggest weaknesses in OT security no longer sit inside the control layer, but at the boundaries where OT connects with people, devices, suppliers and supporting systems.

Incidents across Norway, major European airports, and public-sector operations in Canada and Poland all pointed to the same pattern. The failures that disrupted operations did not originate from OT systems themselves, but from compromises around them.

Global reports released throughout the year reached the same conclusion. The attacks themselves were not becoming more sophisticated — the same weak entry points were simply being exploited again and again. The issue was not technology. It was structure.

As organisations prepare their security priorities for 2026, this shift can no longer be ignored. OT systems are already heavily protected. But if the users, devices, accounts, supply-chain pathways and operational structures leading into OT remain exposed, no amount of internal hardening will be enough.

The four priorities below represent the most actionable areas to address the weaknesses revealed in 2025.

1. Redesign the Access Pathways Leading Into OT

The vast majority of 2025 intrusion attempts began with overly broad or permanently open access routes. Vendor accounts, maintenance logins, always-on remote connections, and administrative privileges far wider than necessary created predictable and easily exploitable entry points.

In 2026, these pathways must be rebuilt. The most immediate actions include:

• Restricting vendor and maintenance accounts to task-specific windows
• Moving away from permanently active remote access towards just-in-time connections
• Separating privileges on engineering workstations to avoid single points of failure
• Physically isolating administrative tools and accounts from internet-facing environments
• Eliminating shared, reused or inherited supply-chain credentials

2025 showed that the problem was not complex attack techniques. It was a poorly designed access structure that left the “front door” wide open.

2. Verify Users and Devices Before They Reach OT

Across every major report and incident analysis in 2025, one message appeared consistently: Intrusions did not begin on the network. They began with users and devices.

Compromised operator or contractor accounts, engineering laptops lacking integrity checks, and unverified portable devices were among the most frequently exploited elements — all of them positioned before OT entry.

For 2026, organisations will need to strengthen verification at this boundary:

• Strong identity validation before access is granted
• Device integrity (Device Trust) checks to prevent compromised endpoints from entering OT
• One-time or non-reusable access methods for supply-chain personnel
• Authentication mechanisms that function even when networks are segmented or offline
• Stricter validation for field devices, shared devices and contractor equipment

If the biggest weaknesses sit at the entrance to OT, then trust must be established before anything crosses that boundary.

3. Consolidate Fragmented Authentication, Access and Activity Logs

One of the most persistent barriers highlighted in 2025 was the fragmentation of logs. When authentication records, access logs and activity trails are split across OT, IT and supply-chain systems, incident responders lose the ability to see what happened, when it happened and where the intrusion began.

For 2026, logging must become a structural priority rather than an afterthought:

• A unified logging framework spanning OT, IT and supply-chain environments
• Consolidated visibility of authentication, access and activity events
• Integrated records for engineering tools, HMIs and remote-access sessions
• Local logging resilience for environments that operate without constant connectivity
• Stronger detection policies based on abnormal access behaviour

Logs are not only for post-incident analysis. They are the foundation for early detection and rapid containment.

4. Build Operational Resilience Around Structure, Not Technology

The large-scale outage across Spain and Portugal and the airport disruptions across Europe reminded the industry of an uncomfortable reality: operational resilience, not cyber sophistication, determines whether services stay running.

When systems are tightly interconnected — across OT, IT and supply-chain services — recovery is no longer a matter of restarting servers or restoring backups. Resilience is a structural question.

In 2026, organisations will need to reinforce this structure:

• Removing single points of failure (SPOFs) across OT–IT–supply-chain links
• Reordering restart and recovery procedures around OT operational priority
• Ensuring alternative authentication and access routes during system outages
• Reducing excessive dependency across interconnected operational services
• Designing operational architectures that can tolerate disruption

In low-resilience environments, cyber incidents and operational failures become indistinguishable — both lead to the same operational collapse.

The Question 2025 Leaves Behind

The incidents of 2025 showed how far adversaries could get. The global reports explained why they got there so easily.

Their shared conclusion is impossible to ignore:

OT is well protected on the inside. The real problem is how easily the door into OT can be opened.

For 2026, this must be the starting point. Rebuilding access structures, validating trust at the edge, unifying visibility, and strengthening operational resilience are not long-term ambitions. They are the most practical, necessary and high-impact changes organisations can make as they enter 2026.