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Rethinking Microsoft Secure Score: Why a Percentage Is Not a Security Posture
Microsoft Secure Score is one of the most widely referenced security metrics in Microsoft 365. It is visible, easy to understand, and often used as shorthand for “how secure” an environment is.
That simplicity is precisely the problem.
Secure Score can be a useful indicator, but it is frequently misunderstood, over-trusted, and misused — particularly at senior and executive levels. This article explains where Secure Score adds value, where it breaks down, and why it should never be treated as a proxy for real security assurance.
In many organisations, Secure Score becomes a convenient shorthand for security maturity. It is easy to reference in reports, simple to trend over time, and visually persuasive to non-technical audiences. Over time, this convenience can subtly shift Secure Score from a supporting metric into a decision-making anchor — a role it was never designed to play.
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At its core, Secure Score measures configuration alignment against Microsoft-recommended controls across Microsoft 365 and Entra ID.
This focus on configuration alignment is not inherently flawed. Standardised recommendations provide a useful baseline for organisations that lack deep security expertise or dedicated resources. Problems arise when this baseline is mistaken for an evaluation of risk, resilience, or attacker capability — areas that require context Secure Score is not designed to capture.
It does not answer:
Secure Score measures presence, not assurance.
Presence confirms that a control exists somewhere in the tenant. Assurance requires confidence that the control operates as intended under real conditions. That confidence only comes from understanding how the control behaves during user error, malicious activity, and operational failure — none of which Secure Score is capable of evaluating.
Security posture is inseparable from business context. An organisation’s industry, regulatory exposure, operational model, and tolerance for disruption all influence which risks matter most. A scoring system that abstracts away this context can offer consistency, but it does so at the cost of relevance.
Every Microsoft 365 tenant is different:
Secure Score does not meaningfully account for this context.
Two organisations can achieve the same score while having:
A “good” score may still coexist with critical weaknesses — particularly around identity, privilege, and monitoring.
This contradiction is common because Secure Score evaluates controls in isolation. It does not account for how weaknesses compound across identity, privilege, and monitoring. As a result, tenants can score well while still containing viable attack paths that exploit the interaction between otherwise “acceptable” configurations.
Secure Score is designed by Microsoft, using Microsoft’s own control model.
That does not make it malicious — but it does make it non-independent.
Vendor-developed metrics inevitably reflect vendor priorities. In the case of Secure Score, this means emphasising feature adoption and configuration completeness rather than operational effectiveness or governance maturity. These priorities are understandable from a platform perspective, but they limit Secure Score’s usefulness as an independent measure of security risk.
Some improvements:
Secure Score is therefore best treated as a Microsoft optimisation tool, not a security assessment.
Vendor-neutral standards (such as NIST or CIS) exist precisely because security requires independent challenge.
One of the most common failure patterns we see is Secure Score being reported upward as a primary security metric.
This creates a dangerous narrative:
When this narrative takes hold, it becomes difficult to justify further security investment. Requests for assessment, testing, or operational improvement are challenged by a metric that appears to say “everything is fine”. Over time, Secure Score stops being a tool for improvement and becomes a barrier to honest risk discussion.
In reality, Secure Score:
Security outcomes do not map cleanly to percentages.
Secure Score often encourages:
This creates checkbox security — controls exist, but no one can explain:
Automation without understanding increases fragility, not resilience.
Automation is most effective when it accelerates well-understood decisions. When it replaces understanding entirely, it increases systemic fragility. Controls are enabled without clarity on their purpose, dependencies are ignored, and failure modes remain unexamined. In these conditions, security posture becomes brittle — impressive on paper, unreliable in practice.
Secure Score is not useless. It works well as:
When framed appropriately, Secure Score can serve as a useful conversation starter. It highlights areas that warrant attention and can help track progress against basic hygiene goals. The key is ensuring that it remains an input into security decision-making rather than the output.
Used correctly, it supports security conversations.
Used incorrectly, it replaces them.
An independent Microsoft 365 security assessment answers very different questions:
Secure Score shows activity. Assessment of Microsoft 365 and Azure shows assurance.
Independent assessment introduces elements that Secure Score cannot provide: challenge, interpretation, and prioritisation. It considers how controls interact, how attackers adapt, and how operational realities influence risk. This is why assessment complements metrics rather than competing with them.
Secure Score is a metric — not a verdict.
Mature security programmes resist the temptation to collapse complex risk into simple numbers. They use metrics to inform judgement, not replace it. Secure Score can be part of that ecosystem, but only when its limitations are understood and its influence appropriately constrained.
It can highlight areas worth attention, but it cannot tell you whether your Microsoft 365 environment would withstand a real attack, satisfy a regulator, or support a defensible risk decision.
Mature organisations treat Secure Score as one input among many, not the destination. Real confidence comes from understanding, validation, and independent challenge — not from a percentage on a dashboard.
Trusted Microsoft Cloud Security Advisor with 27 years experience | Empowering Businesses to Embrace Cloud Innovation with Confidence
