Find notable cyber news and cases, enriched with sources, timelines, and signals.
Home Browse News Feed Stats Watchlists Beta About Contact

Microsoft 365 outage blocking Teams, Exchange Online, and admin center access

Service Disruption
First reported
Last updated
Happening score
H score 25
1 unique sources, 1 articles

Summary

Hide ▲

Microsoft is dealing with a Microsoft 365 outage that is blocking access to Teams, Exchange Online, and the admin center, with some users also unable to complete MFA or Microsoft Entra SSO sign-in. The disruption matters because it is cutting off day-to-day collaboration and administrative access for affected organizations. Microsoft says engineers are actively mitigating the issue by rebalancing dependent service infrastructure.

Related Happenings

Microsoft Teams on macOS repeated location-prompt service disruption

Service Disruption
First: 19.05.2026 19:10 Last: 19.05.2026 19:10 Sources 1

About this happening: Microsoft confirmed a **Microsoft Teams on macOS** service disruption that causes **non-dismissible location prompts** for some users, interrupting normal app use for those who en...

Open Happening

Microsoft Exchange CVE-2026-42897 mitigation advisory

Advisory/Mitigation
First: 15.05.2026 12:40 Last: 15.05.2026 12:40 Sources 1

About this happening: **Microsoft** issued immediate mitigation guidance for **CVE-2026-42897**, reducing risk for **Exchange Server 2016, 2019, and Subscription Edition (SE)** on-premises servers that...

Latest development: 15.05.2026 15:35

Microsoft issued temporary mitigation guidance for CVE-2026-42897 while a patch is still in development, recommending the Exchange Emergency Mitigation (EM) Service, which is enabled by default and can be checked with the Exchange Health Checker script, or the Exchange On-premises Mitigation Tool (EOMT) for disconnected or air-gapped environments. Microsoft noted that the mitigations can disrupt features such as OWA Print Calendar and Inline images, and that servers older than March 2023 cannot receive new mitigations through EM Service.

Open Happening

Microsoft Exchange Server spoofing/XSS flaw under active exploitation (CVE-2026-42897)

Vulnerability
First: 15.05.2026 09:19 Last: 15.05.2026 09:19 Sources 1

About this happening: **CVE-2026-42897** is an **actively exploited** **spoofing/XSS** flaw in **on-premises Microsoft Exchange Server** that can let attackers trigger **arbitrary JavaScript** in a bro...

Open Happening

KongTuke Microsoft Teams initial access campaign

Campaign
First: 14.05.2026 15:12 Last: 14.05.2026 15:12 Sources 1

About this happening: The **KongTuke** campaign now uses **Microsoft Teams** social engineering to gain persistent access to **corporate networks**, shortening initial compromise to **under five minute...

Open Happening

Microsoft Windows 365 Office installation disruption

Service Disruption
First: 13.05.2026 14:53 Last: 13.05.2026 14:53 Sources 1

About this happening: The **Windows 365** service update has introduced a **configuration change** that is blocking **Office downloads and installs** for some customers, disrupting access on cloud PCs....

Open Happening

Timeline

  1. 08.10.2025 21:35 2 articles · 7mo ago

    Microsoft 365 outage disrupts Teams, Exchange Online, and admin center access

    Initial Disclosure

    Microsoft is responding to an ongoing Microsoft 365 outage that is preventing some users from accessing Microsoft Teams, Exchange Online, and the Microsoft 365 admin center, while also causing Multi-Factor Authentication (MFA) and Microsoft Entra single sign-on (SSO) sign-in issues. Microsoft is tracking the issue as an incident on the Service Health Dashboard, providing updates on the Service Health Status page and status.cloud.microsoft, and rebalancing dependent service infrastructure as a near-term mitigation action.

    Show sources
    Open in new tab