Microsoft 365 Hit by New Outage as Users Report Widespread 502 and 503 Errors

Microsoft has confirmed a fresh service degradation affecting its Microsoft 365 suite, with users worldwide reporting an inability to access core applications since the evening of September 16, 2026.

The incident, tracked internally as MO1472904, began at 7:17 PM GMT+5:30 and has been classified by Microsoft as an active service degradation rather than a full outage, though the disruption has already generated a wave of user complaints across enterprise and consumer accounts alike.

According to Microsoft’s admin center advisory, affected users are encountering 502 and 503 HTTP error codes when attempting to reach Microsoft 365 services, a signature pattern typically associated with backend server overload, gateway timeouts, or upstream infrastructure failures rather than authentication or credential issues.

In its most recent update, posted at 7:36 PM GMT+5:30, Microsoft said its engineering teams are reviewing service telemetry alongside user-submitted reports to isolate the root cause and determine appropriate remediation steps. The company has committed to issuing its next update by 3:30 PM UTC, signaling that a resolution timeline remains uncertain at this stage.

We're investigating an issue with users being unable to access some Microsoft 365 services. Further details are provided under MO1472904 in the admin center.

— Microsoft 365 Status (@MSFT365Status) September 16, 2026

This latest disruption arrives amid a turbulent stretch for Microsoft’s cloud productivity ecosystem, which has experienced several high-profile outages throughout 2026, including a multi-day Exchange Online authentication failure in late August and a networking misconfiguration in July that disrupted Teams and SharePoint across North America.

Those earlier incidents were traced to authentication component failures and erroneous network updates, though Microsoft has not yet indicated whether MO1472904 shares a similar underlying cause.

For IT administrators, the immediate priority is monitoring the Microsoft 365 admin center for granular scope-of-impact details, since 502 and 503 errors can affect specific tenants, regions, or service components differently.

Organizations experiencing disruption should avoid unnecessary password resets or configuration changes until Microsoft clarifies the fault domain, as such actions have complicated recovery efforts during past incidents.

Security teams are also advised to distinguish genuine service degradation from potential denial-of-service activity, since error codes alone cannot rule out malicious traffic.

Cyber Security News will continue monitoring MO1472904 and provide updates as Microsoft releases further technical details on the scope and resolution of this incident.

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