Tag Archives: Update

Microsoft Office 0-day vulnerability CVE-2026-21509; Emergency updates available

Posted on 2026-01-27 by guenni

Microsoft Office 2016 to 2024 and Office 365 apps contain a zero-day vulnerability (CVE-2026-21509) that is being actively exploited in attacks. On January 26, 2026, Microsoft published initial information (also about mitigations) and emergency updates for Microsoft Office.

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Windows 11 24H2-25H2 Update KB5074109: Uninstall fails with error 0x800f0905

Posted on 2026-01-25 by guenni

The security updates for Windows released on January 13, 2026 are causing major problems, and Microsoft has had to release corrective updates. In the case of crashes in apps and Outlook Classic, uninstallation was even recommended. This is unfortunate for … Continue reading →

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Windows: Out-of-Band updates fixes Outlook freezes (Jan. 24, 2026)

Posted on 2026-01-25 by guenni

There are various issues caused by the security updates for Windows released on January 13, 2026. Among other things, issues with Outlook Classic when retrieving POP mail or program freezes have been reported. On January 24, 2026, Microsoft released out-of-band … Continue reading →

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Windows 11 24H2/25H2: Citrix Director / Remote Assist fails with update KB5074109

Posted on 2026-01-16 by guenni

Brief information for administrators of Citrix Virtual Desktop environments. I received several reports, that after installing security update KB5074109 from January 13, 2025, for Windows 11 24H2 or 25H2, Citrix Director failed to work. The reason is, that Microsoft Remote … Continue reading →

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Windows Server: Out-of-Band Updates for WSUS vulnerability CVE-2025-59287 (Oct. 23, 2025)

Posted on 2025-10-24 by guenni

[German]There are out-of-band updates (e.g., KB5070883 for Windows Server 2019) that Microsoft released on October 23, 2025. The purpose of these emergency updates is to close a critical vulnerability in WSUS. The remote execution vulnerability CVE-2025-59287 has been rated with … Continue reading →

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Why ISL Online: Critical factors when choosing a remote desktop solution

[Sponsored Post]In the rapidly evolving IT world, choosing the right remote desktop software is critical for organizations that value security, ease of use and reliability. One provider of secure remote access that has been on the market since 2001 is ISL Online, which presents some considerations for choosing such software below. More ...

Windows file preview broken with Oct. 2025 update: Microsoft explains why it's by design – Part 2

Posted on 2025-10-24 by guenni

[German]The security updates for Windows released on October 14, 2025 cause the preview of files (e.g., PDF documents or Office documents) in Explorer to be blocked in some cases. I described the problem in Part 1. On October 22, 2025, … Continue reading →

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Windows: File preview in Explorer broken after October 2025 update – Part 1

Posted on 2025-10-23 by guenni

[German]Die Oktober 2025-Updates für Windows scheinen einen negativen Effekt auf die Vorschau von Dateien im Explorer zu haben. Mir liegen Berichte vor, dass PDF-Dokumente oder andere Dokumentdateien nicht mehr in der Vorschau geöffnet werden – speziell, wenn sie auf Netzwerkfreigaben … Continue reading →

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Windows 11 24H2-25/H2, Server 2025: SID duplicates cause NTLM/Kerberos authentication errors

Posted on 2025-10-23 by guenni

[German]On October 21, 2025, Microsoft issued a statement regarding a problem with NTLM/Kerberos authentication. Authentication errors occur in these operating systems when SIDs are identical on multiple computers and certain updates from August or September 2025 are installed. This is … Continue reading →

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Office Online Server will reach end of support on December 31, 2026.

Posted on 2025-10-23 by guenni

[German]Microsoft announced the end of support for its Office Online Server in a TechCommunity post titled "Announcing the retirement for Office Online Server" on October 21, 2025. After this date, Office Online Server will no longer receive security updates, bug … Continue reading →

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Windows 11 24H2-25H2: Out-of-band Recovery Update KB5070762

Posted on 2025-10-21 by guenni

[German]Microsoft has released an out-of-band recovery update KB5070762 for Windows 11 24H2 and Windows 25H2 on October 20, 2025. This update is intended to update the Win PE environment and fix the issue caused by the October 2025 patch day, … Continue reading →

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