SharePoint Online

Microsoft 365 Outage Hits Exchange Online, Teams and Outlook After November Patch Tuesday

Microsoft 365 experienced a widespread outage on Thursday that disrupted access to Exchange Online mailboxes, Teams, SharePoint Online, Microsoft 365 Copilot and Defender XDR across multiple regions. The company initially attributed problems to users in the Americas before expanding the scope of affected services. Microsoft traced the disruption to a large number of servers failing automated health checks, which increased load on remaining infrastructure without any rise in overall traffic. The incident occurred two days after the November Patch Tuesday release that addressed 1,094 vulnerabilities, including the actively exploited Outlook spoofing flaw CVE-2026-124194. At the time of reporting, Microsoft had found no evidence of malicious activity or cyberattack and continued investigating elevated processor usage on affected servers. The company tested a workaround to bypass the failing health-check component while tracking the issues under incident IDs EX1550543 and MO1550821.

Massive Microsoft 365 Outage Disrupts Outlook, Teams, Copilot and Exchange Online Worldwide

Microsoft is investigating a widespread outage affecting multiple Microsoft 365 services including Outlook, Microsoft Teams, and Copilot. The incident began at 1:26 PM ET on Thursday and impacted Exchange Online, SharePoint Online, Microsoft Defender XDR, Azure, and OneDrive. Microsoft initially attributed the disruption to elevated infrastructure load but later confirmed that a number of servers unexpectedly became unavailable. The company paused all deployments, redistributed connection traffic, and began restarting affected servers to restore capacity. The outage follows a separate Microsoft Teams incident earlier the same day that affected users in North and South America from 9:45 AM to 10:53 AM ET.