Summary

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 .

For more information, read the full story at the original source: SecurityWeek ↗

Vulnerabilities in this story

• CVE-2026-124194 KEV · fix by 2026-11-24 Microsoft 365 Apps for Enterprise, Microsoft Office LTSC EPSS 1.6% 6.5Medium

Also reported by

• BleepingComputer: Massive Microsoft 365 outage disrupts Outlook, Teams, Copilot worldwide ↗
• The Hacker News: Microsoft Patches 1,259 Flaws, Including Exploited Outlook Bug That May Expose NTLMv2 Hashes ↗
• Malwarebytes Labs: Microsoft Patch Tuesday fixes Outlook flaw already under attack ↗
• Security Affairs: Microsoft November Patch Tuesday: one exploited Outlook bug and 30 wormable flaws ↗
• The Register: November Patch Tuesday boasts over 1,000 bugs, one already under attack ↗
• Dark Reading: November Patch Tuesday: An Overflowing Cornucopia of CVEs ↗
• Krebs on Security: Microsoft Fixes Nearly 1,100 Security Vulnerabilities ↗