Microsoft 365 outage disrupts Outlook, Exchange Online and Teams
Original title: Microsoft 365 Outage Disrupts Outlook, Exchange Online and Teams
Microsoft blamed unavailable servers, not higher traffic, and has reported no evidence of a cyberattack.
Microsoft 365 suffered a widespread outage Thursday that first blocked Exchange Online mailboxes in the Americas, then affected Teams, SharePoint Online, Microsoft 365 Copilot, and Defender XDR. Microsoft said many servers became unavailable and remaining systems absorbed normal traffic. Affected servers failed automated health checks; Microsoft was testing a workaround that bypasses that component and investigating high processor use. As of just before 3 p.m. ET, both tracked incidents were service degradations. Service advisories did not link an exploited Outlook spoofing flaw to the outage.
Unconfirmed: Microsoft has not explained the health-check failures or elevated processor use and has disclosed no evidence of a cyberattack.
- Some Google Workspace users could not reach mail through Outlook desktop and mobile clients.
- Exchange Online is tracked as EX1550543 and the broader incident as MO1550821.
- Microsoft was testing a workaround that bypasses failed health-check processing.
- Advisories reported no evidence of malicious activity.
- Vendors
- Microsoft
From the original article
1 min read at securityweek.com
Microsoft says failed server health checks disrupted Outlook and other Microsoft 365 services. The company is still investigating the cause and has disclosed no evidence of a cyberattack. The post Microsoft 365 Outage Disrupts Outlook, Exchange Online and Teams appeared first on SecurityWeek.
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