M365 Message Center

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28.01.2026

Handlung bis

31.01.2027

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Microsoft Defender XDR

Updated January 26, 2026: We have updated the content. Thank you for your patience. [Introduction] We’re retiring the Microsoft Defender for Endpoint (MDE) Advanced Hunting API and Microsoft Defender XDR Advanced Hunting API and transitioning customers to the Microsoft Graph Security API. This update aligns our security integrations with a unified interface and schema across Microsoft Defender products. The Microsoft Graph Security API provides broader data coverage, improved consistency, and better scalability for automation and security workflows. [When this will happen] Retirement start: February 6, 2026 Full retirement: February 1, 2027 After February 1, 2027, the MDE and XDR APIs will no longer function. [How this affects your organization] Who is affected: Organizations using the MDE or XDR Advanced Hunting API for automation, integration, or custom workflows.You are receiving this

Geändert

28.01.2026

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Windows

IMPORTANT: This notice is only relevant for environments where:Microsoft Office is usedScan Cab is used to check for update complianceThe January 2026 Scan Cab was deployed before 2:30 PM PT on January 27, 2026.An updated version of the January 2026 Scan Cab was made available at 2:30 PM PT on January 27, 2026. This Scan Cab includes new metadata corresponding to new updates for Microsoft Office 2016.The new security updates for Microsoft Office released January 26, 2026, included additional protections to address CVE-2026-21509. Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally. See the additional information section of this message for details.How this affects your organization:IT administrators who downloaded the Scan Cab before 2:30 PM PT on January 27, 2026, should re-acquire and re-deploy it

Geändert

26.01.2026

Services

Windows

(Updated 1/26 to adjust Windows Server entries and links)Microsoft released today a resolution for an issue observed after installing the January 2026 Windows security update. This issue may cause applications that open or save files stored in cloud‑backed locations to become unresponsive or display errors. Some installations of Outlook may also become unresponsive and fail to open when PST files are stored in cloud‑backed storage such as OneDrive. An out-of-band (OOB) update was released today, January 24, 2026, to address this issue. This cumulative update includes all protections and improvements from the January 2026 Windows security update released January 13, 2026, as well as from the OOB update released on January 17, 2026 (which introduced fixes for two known issues: remote desktop connections and hibernation failures). This OOB update is available through Windows Update for Wind

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21.01.2026

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Windows

Mark your calendars for February 5, 2026. Windows engineering teams will be hosting a second Ask Microsoft Anything (AMA) on the Microsoft Tech Community to help you get the information you need about updating Secure Boot certificates on your Windows devices before they start expiring in June 2026. Experts will be on camera and in the chat to help you with update scenarios, inventorying your estate, formulating the right deployment plan for your organization, and more. When will this happen:This one-hour AMA event will start at 8:00 AM PST (3:00 PM UTC) on February 5, 2026. What you need to do to prepare:Visit the event page, then select Add to Calendar. Want an event reminder? Log in to the Tech Community and select Attend. Can’t attend at that time? Scroll to the bottom of the event page, then post your questions early where it says “Comment.” The event will be recorded so you can catc

Geändert

17.01.2026

Services

Windows

Microsoft has identified issues upon installing the January 2026 Windows security update. To address these issues, an out-of-band (OOB) update was released today, January 17, 2026.Connection and authentication failures in remote connection applications: This issue affects multiple platforms including Windows 11, version 25H2; Windows 10, version 22H2 ESU; and Windows Server 2025. See the bottom of this message for the complete list of affected products.Devices with Secure Launch might fail to shut down or hibernate: This issue only affects Windows 11, version 23H2.The out-of-band (OOB) update was released today, January 17, 2026, in the Microsoft Update Catalog. If you have not yet deployed the January 2026 Windows security update and your IT environment includes the affected applications and features, we recommend applying this OOB update instead. For more information and installation i

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16.01.2026

Services

Windows

Windows updates released on and after January 13, 2026, introduce the first phase of protections addressing a Kerberos information disclosure vulnerability (CVE‑2026‑20833). These updates introduce new auditing and optional registry controls that devices can use to begin reducing reliance on RC4 encryption. They also help prepare domain controllers for a future shift to AES‑SHA1 as the default Kerberos encryption method for accounts without explicit encryption settings. The initial deployment phase focuses on identifying misconfigurations or dependencies before the second deployment phase begins in April 2026.When this will happen:The initial deployment phase starts January 13, 2026, and introduces new Kerberos audit events that help identify any remaining RC4 dependencies across your environment. This phase also adds the temporary RC4DefaultDisablementPhase registry value, which organiz