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Windows Server 2019 Windows Server 2019 Out-of-band security update
Out-of-band

KB5070883

KB5070883: Cumulative update for Windows Server, version 2019, October 2025. Critical WSUS flaw fixed; synchronization error details stay hidden

In short

Fixes a critical remote code execution flaw in WSUS reporting web services. WSUS synchronization error details are temporarily unavailable after installation.

Does it affect you? Applies to: Devices running Windows Server 2019, x64.

Build
17763.7922
Security
1 fixed · 1 critical
Restart
Required

Microsoft publishes separate notes for this KB for Windows 10.

What changes

Fix 1 change

Windows Server Update Services (WSUS)

  • WSUS reporting web services receive a fix for a remote code execution vulnerability.1
    Addresses CVE-2025-59287.

Improvement 1 change

Servicing stack

  • The component that installs Windows updates gets quality improvements intended to help make update installation more reliable.2
    Includes servicing stack update KB5066585, build 17763.7912.

Known issues

  1. Open Affects: Organizations and IT administrators

    Windows Server Update Services (WSUS) does not display error details

    After this update or later updates, WSUS does not display synchronization error details. This functionality is temporarily removed to address CVE-2025-59287.3

    Workaround status No workaround yet

    Microsoft has not published a manual workaround for this issue yet. Monitor release health until a resolving update is available.

Technical details

Data sheet · Security · Downloads · Components Click to collapse or expand

Data sheet

Released
2025-10-23
Classification
Security Updates
Type
Cumulative update
Restart
Required
Replaces
KB5066586, KB5065428, KB5066187, KB5063877
+8 earlier KB5062557, KB5060531, KB5061978, KB5058392, KB5059091, KB5058922, KB5050008, KB5037425
Replaced by
KB5068791
VersionBuildChannel
2019 17763.7922 General availability

Security

1 vulnerability fixed
1 critical
VulnerabilitySeverityCVSS
CVE-2025-59287
Windows Server Update Service (WSUS) Remote Code Execution Vulnerability
 Critical 9.8

Downloads (Microsoft Update Catalog)

x64 2019
710.2 MB
windows10.0-kb5070883-x64.msu Main update · KB5070883 SHA-1: 273089a4…3b9504

Updated components

9 files changed since the previous update for the same versions.

Sources

Updated
Cited passages from Microsoft's official notes (3)
  1. 1. [Windows Server Update Services (WSUS)] Fixed: This update addresses a remote code execution (RCE) vulnerability that was identified in WSUS reporting web services. support.microsoft.com
  2. 2. This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. support.microsoft.com
  3. 3. After installing this update or later updates, Windows Server Update Services (WSUS) does not display synchronization error details within its error reporting. This functionality is temporarily removed to address the Remote Code Execution Vulnerability, CVE-2025-59287. support.microsoft.com
Checked automatically: 8 of 8 checks passed, 3 quoted passages · compared with Microsoft's page on Nov 6, 2026
  • Quotes found in the official pages: passed
  • Numbers found in the sources: passed
  • Vulnerabilities from the dossier only: passed
  • Links to allowed domains only: passed
  • Every official change covered: passed
  • Readable plain text: passed
  • Changes confirmed by the file list: passed
  • Sources agree: passed

A second AI read the text against the sources: correctness 5/5, clarity 4/5, completeness 5/5. How we work

Published by The Update Bureau. Written with AI from Microsoft's own documents, checked by rules and a second AI. How we work · Report a mistake