The rapid expansion of connected devices has fundamentally changed how organisations operate. From smart sensors and industrial controllers to gateways, cameras, and embedded systems, IoT has become integral to modern business. Digital transformation is accelerating the adoption of IoT technologies, increasing the attack surface and making IoT security a critical component of modern cybersecurity strategies. Yet as these environments grow, a dangerous reality has emerged: many organisations no longer know exactly what is connected to their networks.

In 2026, unmanaged IoT devices represent a significant threat for most organizations and are one of the largest and least understood security risks. These devices often operate silently in the background, outside traditional IT oversight, creating blind spots that attackers actively exploit. The issue is not simply the number of devices, but the lack of identity, ownership, and lifecycle control associated with them. Unmanaged IoT devices are a significant threat to enterprise security.

Introduction to IoT Security

The Internet of Things (IoT) has transformed the modern enterprise, connecting everything from security cameras and smart TVs to complex operational technology (OT) devices. This surge in connected devices has unlocked new efficiencies and business opportunities, but it has also dramatically expanded the attack surface for cyber threats. Unmanaged devices, those not governed by robust security controls, pose a significant risk to sensitive data and critical infrastructure. In fact, recent research shows that more than half of all IoT devices contain at least one critical vulnerability, making them easy targets for threat actors seeking to exploit weak points in the network.

Effective IoT security is now essential for protecting sensitive data and preventing data breaches. Organizations must implement comprehensive security protocols, such as multi-factor authentication, network segmentation, and continuous monitoring, to safeguard their environments. These measures help reduce the risk of unauthorized access and ensure that even as the number of connected devices grows, critical systems remain protected. As the Internet of Things (IoT) continues to evolve, prioritizing security is the only way to keep pace with the risks and maintain the integrity of business operations.

What Are Unmanaged IoT Devices?

An unmanaged IoT device is any connected device that is not properly inventoried, authenticated, or governed by security policy. This may include devices that were deployed years ago, added by third parties, spun up temporarily for projects, or inherited through mergers and acquisitions. In contrast, managed devices are centrally controlled, secured, and included in IT inventories, making them easier to monitor and protect.

Common examples include legacy OT equipment, smart building systems, temporary sensors, remote edge devices, and vendor-managed hardware. These devices often lack centralised monitoring and are rarely integrated into identity or access management processes.

Unmanaged IoT devices are part of a broader set of unmanaged assets that lack proper management and visibility within enterprise networks. The problem is compounded by the fact that many unmanaged devices appear legitimate at a network level. They communicate as expected, perform their intended function, and may never raise an alert—until they are compromised.

Why Unmanaged Devices Create Such a Serious Risk

Unmanaged IoT devices are attractive to attackers precisely because they sit outside normal security controls. They frequently rely on default credentials, shared certificates, or outdated cryptographic material. Outdated software on unmanaged IoT devices further increases security risk by introducing vulnerabilities that can be exploited by attackers. In many cases, organisations cannot easily rotate keys or revoke access without disrupting operations.

Once compromised, these devices can be used as footholds into broader systems, enabling lateral movement across networks or acting as participants in botnets and distributed attacks. Because they are rarely monitored closely, malicious activity can persist undetected for long periods.

This makes unmanaged devices disproportionately involved in breaches and a significant security risk, even when they represent a minority of the total device estate.

The Visibility Problem: You Cannot Secure What You Cannot See

At the heart of the unmanaged device challenge is a lack of visibility. Many organisations rely on asset inventories that are incomplete, outdated, or limited to IT-managed endpoints. IoT and OT environments often operate separately, with different teams, tools, and priorities. To effectively secure these environments, organizations must gain visibility into all devices, including those outside traditional IT management.

Traditional discovery methods struggle in these environments. Devices may use proprietary protocols, intermittent connectivity, or operate behind gateways. Some are deployed in remote or harsh locations where direct access is impossible. This makes it essential to use advanced techniques to find unmanaged devices within the organization’s network, such as monitoring network traffic and device fingerprinting.

As a result, without full visibility into the organization’s network, security teams are forced to make decisions with partial information, unaware of the full scope of their attack surface and left with blind spots.

Why Traditional Security Tools Fall Short

Conventional endpoint security and IAM tools were never designed for IoT at scale. They assume devices can run agents, accept frequent updates, and tolerate downtime. Many IoT devices cannot meet these requirements, and IT teams face significant challenges managing devices with diverse or outdated operating systems that may not support standard security agents.

Attempting to retrofit traditional tools onto IoT environments often leads to operational friction or security gaps. Devices are excluded from controls entirely, or managed through brittle, manual processes that do not scale. The IT department often lacks visibility and control over devices that do not conform to standard operating systems or management protocols, increasing the risk of unmanaged IoT devices bypassing established security measures.

This is why unmanaged IoT devices persist even in organisations with otherwise mature security postures.

Identity Is the Missing Link

The defining characteristic of an unmanaged device is not simply that it is unknown, but that it lacks a strong, verifiable identity. Without identity, there is no reliable way to authenticate the device, enforce policy, or revoke trust when something goes wrong. This is especially challenging for network connected devices that lack proper management, as their presence on the network increases security risks and makes oversight difficult.

Modern IoT security strategies therefore start with identity. By assigning each device a unique cryptographic identity and managing it throughout its lifecycle, organisations can establish trust even in environments where agents and traditional controls are not viable.

This shift reframes the problem: instead of trying to “manage” devices in the traditional sense, security teams focus on managing trust.

Agentless Discovery and Onboarding

In 2026, leading organisations are addressing unmanaged devices through agentless discovery and onboarding. These approaches identify devices based on network behaviour, protocols, and communication patterns, without requiring changes to the device itself.

Once discovered, devices can be onboarded into a controlled security framework where identities are issued, policies applied, and access continuously verified. This allows organisations to bring unmanaged devices under governance without disrupting operations.

Agentless methods are particularly effective in industrial, automotive, healthcare, and critical infrastructure environments, where device modification is impractical or prohibited. Applying these methods across corporate networks is essential to secure all devices and reduce the risk of threats within organizational digital environments.

Access Control and Hidden Risks

Access control is a cornerstone of effective IoT security, ensuring that only authorized users and devices can interact with network resources and sensitive data. However, unmanaged devices often bypass these controls, introducing hidden risks that can compromise critical systems. When devices are connected to the network without proper oversight, they can become entry points for threat actors, who may exploit them to steal sensitive data or disrupt business operations.

To address these vulnerabilities, organizations need to identify unmanaged devices through advanced device discovery tools and agentless monitoring solutions. By analyzing network data and traffic patterns, security teams can detect suspicious activity and quickly pinpoint devices that may be operating outside established security protocols. This proactive approach not only helps prevent lateral movement by attackers but also strengthens access control across the entire environment. By continuously monitoring for hidden risks and enforcing strict access management, businesses can significantly reduce the likelihood of data breaches and protect their most critical assets.

Zero Trust Cannot Work Without Device Visibility

Zero Trust principles depend on continuous verification of identity and posture. In environments full of unmanaged devices, Zero Trust becomes impossible to implement effectively. Monitoring all devices on the corporate LAN is essential to support Zero Trust, as it ensures visibility and control over network activity beyond just cloud or VPN-accessible endpoints.

Every unknown device represents implicit trust—trust that the device is legitimate, behaving as expected, and not compromised. This directly contradicts Zero Trust fundamentals.

By discovering and identifying unmanaged devices, organisations can extend Zero Trust principles across their entire IoT and OT estate, reducing reliance on network-based trust and static assumptions.

Incident Response and Management

A robust incident response and management strategy is vital for organizations facing the growing threat of attacks on unmanaged IoT devices. When a security incident occurs, the ability to respond quickly and effectively can mean the difference between a contained event and a major breach with lasting reputational damage. Security teams must adopt a proactive approach, starting with a comprehensive incident response plan that includes regular vulnerability management, penetration testing, and adherence to security best practices such as network segmentation and endpoint detection.

Maintaining accurate asset inventories—including both managed and unmanaged devices—is essential for rapid identification and isolation of affected systems during an incident. Leveraging advanced technologies like machine learning and threat intelligence can further enhance threat detection, enabling security teams to identify suspicious activity and respond in real time. By reducing the mean time to detect (MTTD) and mean time to respond (MTTR), organizations can minimize the impact of cyber threats on their operations and ensure business continuity. Ultimately, a well-prepared incident response framework is a critical defense against the evolving risks posed by unmanaged IoT devices.

Regulatory and Compliance Implications

Regulatory frameworks increasingly assume that organisations have visibility and control over their connected devices. Requirements around risk management, incident response, and auditability all depend on knowing what assets exist and how they are secured.

Unmanaged devices undermine compliance efforts by introducing undocumented risk. During audits or investigations, the inability to account for all connected devices can lead to findings, delays, or penalties.

As regulations evolve, unmanaged IoT devices are likely to become a focal point for enforcement and scrutiny.

From Blind Spot to Strategic Advantage

Addressing unmanaged IoT devices is not just about reducing risk. Organisations that achieve full device visibility gain operational benefits as well. Today, IoT devices are integral to everyday operations across industries, making comprehensive visibility even more critical. They can make informed decisions about decommissioning legacy systems, optimising infrastructure, and scaling new initiatives with confidence.

What was once a blind spot becomes a source of insight, supporting both security and business objectives.

Final Thoughts

In 2026, unmanaged IoT devices are no longer a niche problem. They are a systemic challenge driven by scale, complexity, and the limitations of traditional security approaches.

The organisations that succeed are those that acknowledge this reality and respond with identity-first, automated, and agentless strategies. By bringing unmanaged devices into a trusted framework, they close one of the most dangerous gaps in modern security architectures.

Solutions developed by companies such as Device Authority are designed specifically to address this challenge, helping organisations move from partial visibility to complete control over their IoT environments. Unmanaged IoT devices include industrial systems, HVAC systems, and other operational technology that are often integrated into supply chains. Vulnerabilities in these devices can disrupt critical physical processes, such as energy distribution or water management, underscoring the importance of robust security for all connected assets.