Microsoft 365 outage disrupts Outlook, Teams, Copilot and Defender XDR
Original title: Massive Microsoft 365 Outage Disrupts Outlook, Teams, Copilot, and Defender XDR Worldwide
Servers failed health checks and went unresponsive again under normal traffic; cause and full restoration are unconfirmed.
A Microsoft 365 connectivity outage that began on November 12 continued into November 13, 2026. Microsoft said users in any region could be affected, after first investigating Exchange Online mailbox access in the Americas. Reported impact includes Outlook, Teams, SharePoint, Copilot, and Microsoft Defender XDR. Engineers found servers unavailable after failed automated health checks and an overwhelmed core process, not elevated traffic. Recovery steps had not produced the expected improvement, and no completion time was given.
Unconfirmed: Microsoft has not confirmed every customer is affected, a root cause, or that service is fully restored.
- Exchange Online is tracked as EX1550543 and broader service restrictions as MO1550821.
- Restarted servers became unresponsive again once normal traffic returned.
- Microsoft is limiting some traffic and considering rollback of recent configuration updates.
- Portal issues do not by themselves mean endpoint protection has stopped.
- 1.Monitor tenant advisories EX1550543 and MO1550821 for service-specific status.
- Vendors
- Microsoft
From the original article
3 min read at gbhackers.com
A major Microsoft 365 outage disrupted cloud connectivity on November 12. It continued into November 13, 2026, as Microsoft worked to restore the affected infrastructure. The company confirmed that users in any region could experience connectivity problems, expanding an investigation initially focused on Exchange Online mailbox access in the Americas.
By Divya · gbhackers.com
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