Microsoft 365 outage passes 10 hours as restored servers fail under load
Original title: Microsoft 365 Massive Outage – Fixes Fail as Restored Servers Keep Going Unresponsive
Downdetector logged over 120,000 Outlook reports from 74 countries; Microsoft says it is not a cyberattack.
A global Microsoft 365 outage that began November 12, 2026, was still running more than 10 hours later on November 13. It started as Exchange Online mailbox failures in the Americas and spread to Outlook, Teams, SharePoint, Copilot and Defender XDR. Servers brought back online become unresponsive again under traffic. Microsoft is limiting traffic, rebuilding some servers on a previous configuration and rerouting load, with partial recovery in some regions and no restoration time. Incidents are EX1550543 and MO1550821. Executive Vice President Charles Lamanna said it was not a security breach.
Unconfirmed: Microsoft has not announced a root cause and has not confirmed a recent change.
- Microsoft first cited load, then said servers dropped out and traffic had not risen.
- Affected services include Planner, To Do, Intune, Purview and Power BI.
- OpenAI and Anthropic reported problems with their Microsoft 365 connectors.
- Workhorse Group postponed third-quarter results to November 16.
- Features that do not depend on Exchange Online reportedly kept working.
- 1.Track incidents MO1550821 and EX1550543 in the Microsoft 365 admin center or Microsoft’s status page.
From the original article
4 min read at cybersecuritynews.com
Microsoft has yet to find a fix that holds for the global Microsoft 365 outage, which has now run for more than 10 hours. Servers that engineers bring back online are falling over again as soon as user traffic reaches them. The outage began on November 12, 2026, and continued through November 13.
By Balaji N · cybersecuritynews.com
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