Microsoft Defender XDR portal outage blocking some capabilities
Service Disruption
Summary
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The Microsoft Defender XDR portal is undergoing an ongoing service disruption that has blocked access to some security capabilities for about 10 hours. The outage has affected customer access to features including advanced threat-hunting alerts and the devices view. Microsoft says the issue stems from a spike in traffic that pushed CPU utilization too high on portal components. Mitigation is underway, and availability has recovered for some impacted customers while Microsoft continues to work with the remaining affected organizations.
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Timeline
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02.12.2025 08:10 2 articles · 7mo ago
Microsoft Defender XDR portal outage blocks access to some capabilities
Initial DisclosureMicrosoft acknowledged an ongoing incident affecting the Defender XDR portal at 06:10 UTC, saying a spike in traffic drove high CPU utilization on components that support portal functionality and blocked access to some capabilities for about 10 hours. Microsoft later applied mitigation measures, increased processing throughput, and reported partial recovery for some customers while continuing to collect HAR traces from impacted organizations and tracking missing advanced threat-hunting alerts and devices not appearing.
Show sources
- Microsoft Defender portal outage disrupts threat hunting alerts — www.bleepingcomputer.com — 02.12.2025 18:10
- Microsoft Defender portal outage disrupts threat hunting alerts — www.bleepingcomputer.com — 02.12.2025 18:10