In which situation is a threat likely to be classified as a risk?

A threat is likely to be classified as a risk when there are no existing controls in place to mitigate that threat. In this context, a risk is identified as a potential event that could cause harm or loss, and the absence of controls implies that the organization is unprotected against the threat. Without any measures implemented to reduce the potential impact or probability of the threat occurring, it can be deemed a significant risk to the organization's assets, operations, and overall security posture. This situation underscores the importance of having adequate controls in place to manage identified threats effectively.

When controls exist but are ineffective, there's still an attempt to manage the risk, albeit unsuccessfully, so it doesn't fit the definition of having no controls at all. Similarly, not understanding the potential impact does not directly classify a threat as a risk; it merely indicates a lack of awareness or knowledge that could complicate risk management. Assessing the likelihood of occurrence is crucial for risk evaluation, but it does not, by itself, constitute a situation where a threat is classified as a risk without the fundamental absence of controls.