2026-01 Cumulative Update for Windows Server 2016 for x64-based Systems (KB5073722)

A security issue has been identified in a Microsoft software product that could affect your system. You can help protect your system by installing this update from Microsoft. For a complete listing of the issues that are included in this update, see the associated Microsoft Knowledge Base article...

CVE-2026-20934

Concurrent execution using shared resource with improper synchronization 'race condition' in Windows SMB Server allows an authorized attacker to elevate privileges over a network...

CVE-2026-20927 Windows SMB Server Denial of Service Vulnerability

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CVE-2026-20926

Concurrent execution using shared resource with improper synchronization 'race condition' in Windows SMB Server allows an authorized attacker to elevate privileges over a network...

CVE-2026-20921

CVE-2026-20921 is a Windows SMB Server vulnerability described as a race condition in a shared resource that could allow an authenticated attacker to elevate privileges over the network. Connected sources indicate this CVE is listed under Windows SMB Server with an exploitability/impact profile (...

CVE-2026-20856

CVE-2026-20856 is a Windows Server Update Services (WSUS) remote code execution vulnerability caused by improper input validation. Exploitation is possible over a network with no user interaction; CVSSv3.1 base score 8.1 (High). Public references note this is addressed by January 2026 security up...

CVE-2026-20856 Windows Server Update Service (WSUS) Remote Code Execution Vulnerability

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CVE-2026-20856

Improper input validation in Windows Server Update Service allows an unauthorized attacker to execute code over a network...

January 13, 2026—KB5073696 (Monthly Rollup)

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January 13, 2026—KB5073697 (Monthly Rollup)

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January 13, 2026—KB5073695 (Monthly Rollup)

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Windows SMB Server Elevation of Privilege Vulnerability

Concurrent execution using shared resource with improper synchronization 'race condition' in Windows SMB Server allows an authorized attacker to elevate privileges over a network...

January 13, 2026—KB5073698 (Monthly Rollup)

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January 13, 2026—KB5073457 (OS Build 20348.4648)

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January 13, 2026—KB5073379 (OS Build 26100.32230)

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January 13, 2026—KB5073450 (OS Build 25398.2092)

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January 13, 2026—KB5073700 (Security-only update)

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January 13, 2026—KB5073722 (OS Build 14393.8783)

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January 13, 2026—KB5073723 (OS Build 17763.8276)

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Windows SMB Server Elevation of Privilege Vulnerability

Concurrent execution using shared resource with improper synchronization 'race condition' in Windows SMB Server allows an authorized attacker to elevate privileges over a network...