💡 Our Technical Review in summary
Summary
On February 23, 2026, users in North America experienced authentication failures when attempting to access Microsoft 365 services. The issue specifically affected organizations leveraging Cisco/Duo as their third-party Multi-Factor Authentication (MFA) provider. Investigations confirmed that Microsoft services remained operational, and the root cause was a service disruption within the Cisco/Duo environment.
Impact
Impacted users encountered 504 gateway timeout errors or general authentication failures during the sign-in process for any Microsoft 365 service requiring MFA. This incident was localized to the North American region and specifically targeted authentication flows involving the third-party provider.
Status
Resolved. The incident lasted approximately two hours and 38 minutes (2:00 PM UTC – 4:38 PM UTC). Cisco/Duo deployed a fix within their environment to resolve the underlying issue. Microsoft has monitored service telemetry to confirm successful authentication attempts and ongoing stability. No further action is required from IT Administrators.
Microsoft Official Issue Details
User Impact
Some users may have experienced issues accessing Microsoft 365 services, particularly during sign‑in or authentication.
Status: investigationSuspended
Service: Microsoft 365 suite
Classification: incident
Origin: microsoft
Updates
- 2026-02-23 17:25
Title: Users may experience issues when trying to access services that require Multi-Factor Authentication (MFA)User impact: Some users may experience issues accessing Microsoft 365 services, particularly during sign‑in or authentication.
More Info: Customers in North America who leverage Cisco/Duo in their MFA sign-in flow were impacted.
Final status: We’ve confirmed that the reported impact has been mitigated. Our investigation determined that Microsoft services were operating as expected throughout the incident. We’ve confirmed with a third‑party authentication provider (Cisco/Duo) that a fix deployed within their environment has resolved the issue, and we’re seeing successful authentication attempts.
Scope of impact: This issue may have affected any user within your organization leveraging MFA for sign-in. We’ve confirmed the following region(s) were impacted by this issue: North America. Additional impacted region(s) may be included as our investigation continues.
Start time: Monday, February 23, 2026, at 2:00 PM UTC
End time: Monday, February 23, 2026, at 4:38 PM UTC
Preliminary root cause: A third‑party authentication provider experienced an issue within their environment, which resulted in authentication failures when users attempted to sign in to Microsoft services that depend on that provider.
Next steps: This incident is considered resolved by a third-party without Microsoft action. We’ll continue to monitor service telemetry to ensure ongoing stability.
This is the final update for the event.
- 2026-02-23 16:30
Title: Users may experience issues when trying to access services that require Multi-Factor Authentication (MFA)User impact: Some users may experience issues accessing Microsoft 365 services, particularly during sign‑in or authentication.
Current status: We’re reviewing Microsoft Entra sign‑in logs and related network telemetry following reports of 504 gateway timeout errors affecting sign‑in using Multi-Factor Authentication (MFA) for Microsoft 365 services. In parallel, we’re also analyzing third-party authentication dependencies and interactions to better understand the potential source of the issue.
Scope of impact: This issue may affect any user within your organization leveraging MFA for sign-in. We’ve confirmed the following region(s) are impacted by this issue: North America. Additional impacted region(s) may be included as our investigation continues.
Next update by: Monday, February 23, 2026, at 5:30 PM UTC
- 2026-02-23 15:57
This quick update is designed to give the latest information on this issue.We’re investigating an issue in the North America region where users may be experiencing 504 gateway timeout errors when trying to access services that require Multi-Factor Authentication (MFA). We’re reviewing Microsoft Entra logs and network telemetry signals to isolate the potential source of the issue.
- 2026-02-23 15:26
Title: Users may experience issues when trying to access services that require Multi-Factor Authentication (MFA)User impact: Some users may experience issues accessing Microsoft 365 services, particularly during sign‑in or authentication.
Current status: We’re investigating reports of impact to M365 services and we’re analyzing service telemetry to identify the specific source of the issue, and any next steps to mitigate impact.
Scope of Impact: This issue may affect any user within your organization. We’ve confirmed the following region(s) are impacted by this issue: North America. Additional impacted region(s) may be included as our investigation continues.
Next update by: Monday, February 23, 2026, at 4:30 PM UTC
- 2026-02-23 14:53
Title: We’re looking into a potential problem impacting Microsoft 365 servicesUser impact: We’re checking for potential impact to your users.
Current status: We’re investigating a potential issue with the Microsoft 365 service and checking for impact to your organization. We’ll provide an update within 30 minutes.
