Skip to the content
The Update Bureau
.NET Framework 4.8 .NET Framework 4.8 Security update
Patch Tuesday

KB5120702

KB5120702: Cumulative update for .NET Framework, version 4.8, on Windows 10 1607 and Windows Server 2016, August 2026. Six runtime vulnerabilities addressed; WPF print failures later resolved

In short

The update addresses six .NET Framework vulnerabilities. Some WPF printing failures associated with the August update are resolved in the September and October 2026 updates.

Does it affect you? Applies to: Devices running Windows 10, version 1607, or Windows Server 2016 with .NET Framework 4.8 installed.

File version
4.8.4805.0
Security
6 fixed
Restart
Required

What changes

Fixes 6 changes

.NET Framework

6 items
  • Addresses CVE-2026-65810, an elevation-of-privilege vulnerability.1
  • Addresses CVE-2026-62872, an elevation-of-privilege vulnerability.2
  • Addresses CVE-2026-62886, a remote code execution vulnerability.3
  • Addresses CVE-2026-62897, a remote code execution vulnerability.4
  • Addresses CVE-2026-70354, a remote code execution vulnerability.5
  • Addresses CVE-2026-62902, an information disclosure vulnerability.6

Known issues

  1. Resolved Affects: Everyone

    After installing the August 2026 .NET Framework cumulative update, some WPF applications may fail with a System.IO.File…

    Some WPF apps may fail with a System.IO.FileFormatException when printing or generating PDF/XPS content that uses certain fonts, including Calibri. The September 2026 .NET Framework cumulative update and later updates resolve this issue.7

    How to apply the workaround Workaround

    As a temporary measure, an affected app can enable the AppContext switch in its config file, only when needed to address the failure.7

  2. Resolved Affects: Everyone

    After installing the August 2026 .NET Framework cumulative update, WPF applications that print—or display print preview…

    WPF apps may fail while loading an in-memory XPS document for printing or print preview when its package identity uses an absolute pack URI. The October 2026 .NET Framework cumulative update and later updates resolve this issue.8

    How to apply the workaround Workaround

    If the app can be rebuilt, use an absolute package identity that does not use the pack scheme. If it cannot be rebuilt, enable the AppContext switch in the app config file as a temporary measure when needed.8

    Step-by-step workaround instructions
    2 steps
    Show steps Hide steps
    Step-by-step procedure
    1. If the app can be rebuilt, change the absolute package identity to one that does not use the pack scheme, such as xpspack://<guid>.xps.
    2. If the app cannot be rebuilt, enable Switch.System.Windows.DisableXpsPackageBoundaryRestriction by setting it to true in the application config file.

Technical details

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

Data sheet

Released
2026-08-11
Classification
Security Updates
Type
Cumulative update
Restart
Required
Replaces
KB5101007, KB5087065
Replaced by
KB5126047
VersionFile versionChannel
4.8 4.8.4805.0 General availability

Security

6 vulnerabilities fixed
4 important 2 not rated
VulnerabilitySeverityCVSS
CVE-2026-62872
.NET Framework Elevation of Privilege Vulnerability
 Important 8.8
CVE-2026-65810
.NET Framework Elevation of Privilege Vulnerability
 Important 7.8
CVE-2026-70354
.NET Core Remote Code Execution Vulnerability
 Important 7.8
CVE-2026-62897
.NET Framework Remote Code Execution Vulnerability
 Important 7.0
CVE-2026-62886
.NET Elevation of Privilege Vulnerability
 Not rated —
CVE-2026-62902
.NET Information Disclosure Vulnerability
 Not rated —

Downloads (Microsoft Update Catalog)

x64 Windows Server 2016 / Windows 10 Enterprise LTSB 2016
58.6 MB
windows10.0-kb5120702-x64-ndp48.msu Main update · KB5120702 SHA-1: 69e7c691…78da0a
x86 Windows 10 Enterprise LTSB 2016
34.6 MB
windows10.0-kb5120702-x86-ndp48.msu Main update · KB5120702 SHA-1: 6fa02d68…938e70

Updated components

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

Top changed componentsFiles
WPF24
ASP.NET10
.NET runtime (CLR)4

Page history

  1. Added CVE-2026-62897 (Important)

Sources

Updated
Cited passages from Microsoft's official notes (8)
  1. 1. This security update addresses an elevation of privilege vulnerability detailed in [CVE-2026-65810.] support.microsoft.com
  2. 2. This security update addresses an elevation of privilege vulnerability detailed in [CVE-2026-62872.] support.microsoft.com
  3. 3. This security update addresses a remote code execution vulnerability detailed in [CVE-2026-62886.] support.microsoft.com
  4. 4. This security update addresses a remote code execution vulnerability detailed in [CVE-2026-62897.] support.microsoft.com
  5. 5. This security update addresses a remote code execution vulnerability detailed in [CVE-2026-70354.] support.microsoft.com
  6. 6. This security update addresses an information disclosure vulnerability detailed in [CVE-2026-62902.] support.microsoft.com
  7. 7. Applications may mitigate the issue by enabling the Switch.MS.Internal.TtfDelta.DisableCmapAndSbitOverflowProtection AppContext switch in the app config file, as shown below. support.microsoft.com
  8. 8. Applications that can be rebuilt should use an absolute package identity that does not use the pack scheme—for example, xpspack://<guid>.xps. support.microsoft.com
Checked automatically: 7 of 8 checks passed, 8 quoted passages · compared with Microsoft's page on Oct 20, 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: not passed

A second AI read the text against the sources: correctness 4/5, 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