Microsoft’s upcoming enforcement change for Conditional Access in Entra ID is a clear pivot toward consistency and defense‑in‑depth: policies that target All resources will now be evaluated even when those policies include resource exclusions, and sign‑ins that request only minimal OpenID Connect (OIDC) or directory scopes may begin to receive Conditional Access challenges such as MFA or device compliance checks where they previously did not. This adjustment, rolling out beginning March 27, 2026 and completing through June 2026, closes a known enforcement gap and has direct operational implications for organizations that rely on custom or legacy apps which request only a small set of scopes during authentication.
Conditional Access has been a cornerstone control for modern Microsoft identity security, giving administrators the ability to require multifactor authentication (MFA), device compliance, session controls, and other access conditions based on user, device, app, and risk signals. Historically, administrators could build policies targeting All resources while excluding specific apps (resource exclusions) to avoid unintended blocks to commonly used or legacy applications.
To reduce the risk of accidental access denials, Microsoft previously exempted a set of low‑privilege scopes from evaluation when a policy targeted All resources but had any resource exclusions. Those scopes — including common OIDC and basic directory scopes such as openid, profile, email, offline_access, and User.Read — were treated as too low‑risk to trigger CA enforcement when the target policy contained exclusions. That behavior created a practical loophole: some sign‑ins could bypass Conditional Access controls simply because a client asked for only those basic scopes.
Under the new enforcement model, Microsoft now treats those scopes as directory access for the purposes of Conditional Access evaluation, mapping them to the Azure AD Graph resource in the policy engine and applying the policy consistently even if resource exclusions exist. The result is predictable, consistent enforcement for sign‑in flows — and for some tenants, an immediate change in user behavior at sign‑in.
Note: the mapping behavior only applies in the specific case where the client application requests only those minimal scopes. If the client requests additional Graph scopes (for example, mail.send, Files.ReadWrite) CA evaluation behaves according to existing rules and the application‑specific target configuration.
After rollout, because the CRM SPA requests only the minimal OIDC scopes, sign‑ins are now evaluated under the All resources policy and users are prompted for device compliance verification. Sales reps using unmanaged devices are blocked until they register or comply. The fix: register the app properly, update its auth flow to include additional scopes and/or migrate to a model where the app’s enterprise registration can be managed for CA exceptions during the transition.
Longer term, this change nudges organizations toward modern identity practices:
Administrators should treat the March–June 2026 rollout window as both an opportunity and a deadline: use the period before and during rollout to inventory, test, and remediate. The cost of inaction is straightforward: potential sudden MFA prompts and broken authentication flows for apps that were implicitly relying on the old exemption.
Prioritize remediation for:
Conclusion
Microsoft’s enforcement update removes an inconsistent exception in Conditional Access that had practical security and operational implications. The change is narrowly targeted, clearly communicated, and rolled out with a set timeline beginning March 27, 2026 and completing by June 2026. With directed effort — inventorying policies, testing affected apps, converting legacy flows to supported authentication models, and preparing users and support teams — organizations can close the gap without disrupting business operations while substantially improving their identity security posture.
Source: Petri IT Knowledgebase Microsoft Entra ID to Close Conditional Access Loophole
Background
Conditional Access has been a cornerstone control for modern Microsoft identity security, giving administrators the ability to require multifactor authentication (MFA), device compliance, session controls, and other access conditions based on user, device, app, and risk signals. Historically, administrators could build policies targeting All resources while excluding specific apps (resource exclusions) to avoid unintended blocks to commonly used or legacy applications.To reduce the risk of accidental access denials, Microsoft previously exempted a set of low‑privilege scopes from evaluation when a policy targeted All resources but had any resource exclusions. Those scopes — including common OIDC and basic directory scopes such as openid, profile, email, offline_access, and User.Read — were treated as too low‑risk to trigger CA enforcement when the target policy contained exclusions. That behavior created a practical loophole: some sign‑ins could bypass Conditional Access controls simply because a client asked for only those basic scopes.
Under the new enforcement model, Microsoft now treats those scopes as directory access for the purposes of Conditional Access evaluation, mapping them to the Azure AD Graph resource in the policy engine and applying the policy consistently even if resource exclusions exist. The result is predictable, consistent enforcement for sign‑in flows — and for some tenants, an immediate change in user behavior at sign‑in.
What’s changing in practical terms
The enforcement shift, explained simply
- If a tenant has a Conditional Access policy that targets All resources and also lists one or more resource exclusions, Microsoft used to exempt certain low‑privilege OIDC and directory scopes from that policy’s enforcement.
- After the change, those previously exempted scopes will be evaluated against the All resources policy. That means sign‑ins that previously bypassed CA — because the client requested only basic scopes — may now be subject to enforcement actions like MFA prompts or device compliance checks.
- The change is scoped: it only affects tenants that have an All resources policy with resource exclusions. Tenants that do not have that policy configuration are not affected.
Timeline (verified)
Microsoft will begin rolling out the enforcement change on March 27, 2026, with the progressive rollout finishing across cloud environments by June 2026. Administrators will receive tenant notifications through Microsoft 365 Message Center if their configuration is impacted.Which sign‑in flows are affected
Sign‑ins most likely to be impacted are those initiated by applications that request only the small set of OIDC or directory scopes enumerated in Microsoft’s guidance. Typical examples include:- Native clients and single‑page applications (SPAs) requesting OIDC scopes such as openid, profile, email, offline_access, and User.Read.
- Confidential clients (server‑side apps) requesting listed directory scopes (for example, User.Read, User.Read.All, User.ReadBasic.All and certain People/Group read scopes) and nothing beyond them.
- Legacy or custom apps that rely on minimal scopes primarily to populate a user profile or determine group membership during sign‑in.
The specific scopes and the mapping behavior
Microsoft’s change explicitly lists the previously excluded low‑privilege scopes and explains the new mapping:- Native clients and SPAs:
- Azure AD Graph: email, offline_access, openid, profile, User.Read
- Microsoft Graph: email, offline_access, openid, profile, User.Read, People.Read
- Confidential clients (if excluded from the All resources policy):
- Azure AD Graph: email, offline_access, openid, profile, User.Read, User.Read.All, User.ReadBasic.All
- Microsoft Graph: email, offline_access, openid, profile, User.Read, User.Read.All, User.ReadBasic.All, People.Read, People.Read.All, GroupMember.Read.All, Member.Read.Hidden
Note: the mapping behavior only applies in the specific case where the client application requests only those minimal scopes. If the client requests additional Graph scopes (for example, mail.send, Files.ReadWrite) CA evaluation behaves according to existing rules and the application‑specific target configuration.
Who will be impacted — an administrator’s short checklist
This change is narrowly targeted, but it’s important to locate any place in your tenant where the pattern below exists:- You have a Conditional Access policy that targets All resources.
- That policy contains one or more resource exclusions (for specific apps).
- You have custom, legacy, or in‑house applications that request only OIDC or the limited directory scopes listed above.
- Those applications cannot currently handle Conditional Access challenges like MFA, device compliance checks, or other access controls.
Impact analysis: security benefits and operational friction
Security benefits (why Microsoft is doing this)
- Consistent enforcement: The biggest security win is consistency. Policies targeting All resources should apply broadly and predictably; this change removes an inconsistent exemption that could be used by attackers or misconfigured apps to avoid MFA enforcement.
- Reduced bypass surface: By treating basic scopes as directory access, Microsoft reduces a subtle bypass avenue where attackers could exploit apps that request minimal scopes to perform reconnaissance or first‑stage access.
- Alignment with defense‑in‑depth: The change is part of Microsoft’s broader Secure Future Initiative — an ongoing effort to harden identity controls, remove legacy behaviors, and close attack surfaces introduced by operational exceptions.
Operational risks and friction
- Unexpected user prompts: Users of affected applications may suddenly receive MFA prompts or device compliance blocks. If the app’s user experience is not prepared for interactive challenges, this will cause service interruptions.
- Legacy app compatibility: Some older apps (or service account integrations) were never designed to interact with modern Conditional Access challenges. Those apps may break or require rework.
- Support load: Helpdesk and IT will likely see an uptick in tickets if the change affects critical productivity apps or background services that trigger user prompts during normal usage.
- Third‑party integrations: Connector services or third‑party integrations that rely on minimal scopes might behave differently if they can’t complete through a CA challenge flow.
Preparing your tenant: a step‑by‑step operational playbook
- Inventory CA policies and apps
- Identify all Conditional Access policies that target All resources.
- Within those policies, list any resource exclusions.
- Create an app list of enterprise and registered apps that might request only minimal scopes.
- Audit application scopes
- For each app in your inventory, determine the scopes requested at sign‑in.
- Flag apps that request only the minimal OIDC/directory scopes listed earlier.
- Prioritize by business impact
- Rank impacted apps by business criticality and user count.
- Identify non‑interactive service accounts and automation flows that cannot respond to interactive CA challenges.
- Test in a controlled tenant or pilot group
- Use a staging tenant or pilot user group to enable a test policy mirroring production.
- Simulate sign‑ins from affected apps to observe the user experience and identify failure modes.
- Remediate or update apps
- For interactive apps: ensure they can present and handle MFA prompts and device compliance checks.
- For non‑interactive service accounts: convert to app‑only flows with appropriate app registration and service principals, or rearchitect to use daemon app patterns that support the required tokens.
- Adjust Conditional Access selectively (if needed)
- Where immediate remediation is infeasible, consider temporary mitigations such as:
- Explicitly including the affected app in CA targeting (instead of relying on All resources exclusions).
- Creating an exception with limited scope and time‑bounded duration while you update the application.
- Avoid creating broad, permanent exceptions that weaken posture.
- Communicate to users and support teams
- Publish a communications plan explaining expected changes and potential MFA prompts.
- Prep helpdesk with troubleshooting steps for device compliance and MFA registration issues.
- Monitor post‑rollout
- Use sign‑in logs and Conditional Access insights to identify broken flows or increased failures.
- Track related helpdesk tickets and app telemetry to close out remediation tasks.
Technical mitigations and migration strategies
Update applications to handle Conditional Access
Interactive client apps should be updated to support the modern authentication flow where Conditional Access challenges are possible. Short‑term changes include:- Implementing proper OAuth/OIDC authentication flows capable of interactive challenge handling.
- Ensuring apps redirect to Microsoft’s authentication endpoints to allow prompt display and challenge completion.
- Handling refresh token behaviour and offline access in ways that don’t require bypassing CA gates.
Move service principals into modelled patterns
Non‑interactive flows and daemon apps should run under service principals or managed identities rather than relying on users or legacy token behaviors. Microsoft has been moving to service principal required and no SP‑less auth models, so registering proper enterprise app objects and granting least‑privilege permissions will both improve security and ensure compatibility.Consider Conditional Access targeting adjustments
Where an app legitimately cannot process Conditional Access challenges, consider:- Converting policy target logic to explicitly target the problematic app with a policy that includes an exception that’s time‑bound and tightly scoped.
- Using Named Locations, trusted device tags, or other contextual signals to reduce user friction while you migrate the app.
- Avoid creating open exclusions under All resources that broadly weaken enforcement.
Real‑world examples (hypothetical scenarios)
Scenario A — A legacy CRM Single‑Page App (SPA)
A small sales team uses an on‑premises CRM exposed through an SPA that requests basic profile and User.Read scopes to display user info at login. The org has an All resources CA policy requiring device compliance, but excluded the CRM app from that policy to prevent lockouts during a previous migration.After rollout, because the CRM SPA requests only the minimal OIDC scopes, sign‑ins are now evaluated under the All resources policy and users are prompted for device compliance verification. Sales reps using unmanaged devices are blocked until they register or comply. The fix: register the app properly, update its auth flow to include additional scopes and/or migrate to a model where the app’s enterprise registration can be managed for CA exceptions during the transition.
Scenario B — Background synchronization agent
A monitoring agent uses a user account to refresh tokens against Microsoft Graph using only User.Read and offline_access. The agent cannot respond to MFA prompts, so after the change it fails to refresh its token. The remediation path: convert the agent to an app‑only daemon using a client credential flow with a properly configured service principal and least‑privilege permissions.Testing and validation guidance
- Use a test tenant or create test users within production with limited scope to avoid wide disruption.
- Validate both interactive and non‑interactive authentication flows from all client types: native, SPA, confidential clients, and server‑to‑server daemons.
- Monitor Azure AD sign‑in logs to capture Conditional Access evaluation details and failure reasons. Look specifically for changes in the “Conditional Access” evaluation status for sign‑ins that previously showed no enforcement.
- Test device compliance flows (Intune enrollment, compliant device checks) and confirm that users can complete the required remediation when prompted.
- If you use a third‑party IdP proxy or CASB, test how those intermediaries handle challenge flows and tokens that were previously exempted.
Policy design considerations going forward
- Prefer explicit, least‑privilege targeting over broad exclusions. Excluding apps from All resources should be rare and well‑documented.
- Move away from relying on implicit exemptions caused by scope semantics. Design policies with explicit intent and test coverage.
- Leverage Conditional Access insights and reporting to detect edge cases where apps request only minimal scopes — this can be an early indicator that an app may be affected by enforcement changes.
- Consider layered controls: use authentication strength and continuous access evaluation (CAE) where appropriate to provide richer signals beyond simple scope checks.
Communication tips for IT teams
- Announce the expected rollout window (starting March 27, 2026, completing by June 2026) and explain who is affected. Be precise about dates when communicating to reduce confusion.
- Provide clear remediation instructions and self‑service guidance for common issues, such as how to register for MFA, how to update a device to compliant status, and how to report a broken integration.
- Prepare escalation playbooks for critical app outages — include steps to temporarily relax a policy safely, how to reconfigure an app registration, and how to convert user‑based auth to app‑only flows.
Security trade‑offs and long‑term perspective
This enforcement change is a net positive for identity security: it reduces obscure bypasses and increases the predictability of Conditional Access. The trade‑off is increased operational effort for administrators and developers, particularly in environments with many legacy integrations.Longer term, this change nudges organizations toward modern identity practices:
- Proper app registration and service principal lifecycle management.
- Use of app‑only authentication for non‑interactive scenarios.
- Reduced reliance on exceptions and ad hoc workarounds.
Actionable checklist (quick reference for admins)
- Identify any CA policy that targets All resources with exclusions.
- List apps that request only minimal OIDC/directory scopes.
- Prioritize apps by criticality and user impact.
- Test sign‑ins in a pilot ring before March 27, 2026.
- Update interactive apps to handle CA challenges; convert non‑interactive flows to service principals or managed identities.
- Prepare communication and support materials for users.
- Monitor sign‑in logs post‑rollout and remediate issues promptly.
Final assessment and recommendations
Microsoft’s decision to close this enforcement loophole improves the consistency and robustness of Conditional Access in Entra ID and reduces a subtle attack surface that could have been leveraged to avoid MFA and device checks. For security‑minded organizations, the change is welcome and aligns with modern identity best practices.Administrators should treat the March–June 2026 rollout window as both an opportunity and a deadline: use the period before and during rollout to inventory, test, and remediate. The cost of inaction is straightforward: potential sudden MFA prompts and broken authentication flows for apps that were implicitly relying on the old exemption.
Prioritize remediation for:
- Business‑critical apps with large user bases,
- Non‑interactive background services that cannot handle interactive CA challenges,
- Any integration that touches production systems during business hours.
Conclusion
Microsoft’s enforcement update removes an inconsistent exception in Conditional Access that had practical security and operational implications. The change is narrowly targeted, clearly communicated, and rolled out with a set timeline beginning March 27, 2026 and completing by June 2026. With directed effort — inventorying policies, testing affected apps, converting legacy flows to supported authentication models, and preparing users and support teams — organizations can close the gap without disrupting business operations while substantially improving their identity security posture.
Source: Petri IT Knowledgebase Microsoft Entra ID to Close Conditional Access Loophole
