AADSTS53003 — Access blocked by Conditional Access
What does this error mean?
The sign-in is blocked by a Conditional Access policy.
Where can it appear?
This error may appear in application logs, client messages, monitoring systems or protocol traces. Keep the complete timestamp, request context and surrounding events before troubleshooting.
Likely causes
- Tenant, application or identity configuration
- Conditional Access or MFA policy
- Incorrect application identifier, redirect URI or sign-in context
Checks and resolution
- Open Microsoft Entra sign-in logs
- Identify the policy or application object involved
- Correct the targeted configuration instead of weakening global security
Caution : Avoid broad exclusions from MFA or Conditional Access for a single troubleshooting case.