As connected devices multiply, one overlooked vulnerability could cascade into chaos
Cyber Security • February 19, 2026 • Written by: Mike Boreham • Read time: 1 min
Across the UK public sector, connected technologies are rapidly reshaping how services operate. Smart transport systems, sensor‑driven infrastructure, digitally enabled public spaces and more promise efficiency, insight and new ways of delivering value. There is, however, a growing tension at the heart of this transformation:
Don’t let everything, everywhere, all at once build in vulnerability instead of resilience?
Modern systems are rarely stand alone. They interact. They share data. They depend on one another in ways that blur the edges of responsibility. They widen the potential blast radius of failure. A single misconfigured sensor, insecure API, or vulnerable supplier component can have implications far beyond the failing component’s immediate environment.
In response to this, the National Cyber Security Centre (NCSC) stresses the importance of designing resilience in to connected systems from the outset. The NCSC Connected Places Cyber Security Principles reinforce this simple but vital message: resilience is not something to be layered on afterwards. it must be part of the architecture, the data model and the operating culture from day one. The NCSC defines a connected place as:
“a community that integrates information and communication technologies and IoT devices to collect and analyse data to deliver new services to the built environment and enhance the quality of living for citizens”.
(source: https://www.ncsc.gov.uk/collection/connected-places-security-principles )
For many organisations, the first step is gaining a full understanding of the environment they are securing. Connected systems often evolve organically. New technologies are grafted onto legacy platforms. Multiple suppliers contribute components over time to replace or enhance functionality. Mapping the technology that is out there, the assets involved, the data flows between them, the suppliers who support, or indeed once supported, them and the dependencies that link them all need to be listed. Only by doing this can you provide the foundation for robust, threat informed design.
You cannot secure what you cannot fully see.
Once the landscape is understood, resilience becomes a design discipline rather than a firefighting exercise. Secure-by-design principles can then be used to ensure that each component, whether modern or decades old, is governed by strong identity protections. Their configuration can be secured, data flows encrypted and lifecycle management applied. Equally important is the way systems are interconnected. Appropriate levels of segmentation and isolation ensure that if a vulnerable component does fail, it fails safely and on its own. It does not drag down an entire service ecosystem down with it.
Monitoring too must evolve. In our CyberUK 2026 Week 2 blog, we discussed the NCSC’s Cyber Assessment Framework (CAF) 4.0 (https://eu1.hubs.ly/H0rLzDN0 ). In this we discussed the shift across UK public services is from passive logging to active behavioural detection. In a connected environment, this becomes especially important. Understanding what “normal” looks like makes it possible to spot anomalies early, investigate them quickly, and contain potential threats before they spread.
What should your devices, data flows, user interactions and system behaviours really look like? Are they behaving oddly? What will you do to check?
All of this leads us to the central principle that underpins resilience in connected systems:
Don’t plan for perfection. Manage imperfection.
In a sea of distributed digital services, interruptions will happen. What matters is ensuring those interruptions are contained, managed and recovered from without damaging public trust or safety. Systems designed with resilience in mind can be made to degrade gracefully, rather than collapsing catastrophically. Build your fortress with rings of defence, rather than a wall you hope cannot be breached.
Connected technologies are now deeply embedded in the way the UK public sector operates. Resilient connected technologies must be equally embedded, not as an afterthought, but as a solid backbone through everything that connects, anywhere.
At CyberUK 2026 – Stand F29, we will be discussing connected systems vulnerabilities with delegates and exploring:
- How to model connected system interdependencies
- How NCSC’s Connected Places principles translate into practical design
- How to prevent cascading failures through behavioural monitoring
- How to embed resilience into complex, supplier driven ecosystems‑driven ecosystems
- What connected resilience looks like in transport, local government and healthcare
Connected technologies will define the next decade of public sector capability. Designing resilience into them will define the next decade of public sector trust.‑sector capability. Designing their resilience will define the next decade of public‑sector trust.