Win Update KB5066128 .NET Framework 3.5 and 4.8.1 Cumulative Update for Windows 11 (25H2) - Oct. 14



 Microsoft Support:

The October 14, 2025 update for Windows 11, version 25H2 includes security and cumulative reliability improvements in .NET Framework 3.5 and 4.8.1. We recommend that you apply this update as part of your regular maintenance routines. Before you install this update, see the Prerequisites and Restart requirement sections.

Summary​

Security Improvements

CVE-2025-55248 - .NET Framework Information Disclosure vulnerability
This security update addresses an information disclosure vulnerability detailed in CVE-2025-55248.

Quality and Reliability Improvements
There are no new Quality and Reliability Improvements in this update.

Known issues in this update​

Microsoft is not currently aware of any issues in this update.

How to get this update​

Install this update

Release ChannelAvailableNext Step
Windows Update and Microsoft UpdateYesNone. This update will be downloaded and installed automatically from Windows Update.
Windows Update for BusinessYesNone. This update will be downloaded and installed automatically from Windows Update.
Microsoft Update CatalogYesTo get the standalone package for this update, go to the Microsoft Update Catalog website.
Windows Server Update Services (WSUS)YesThis update will automatically sync with WSUS if you configure as follows:
Product: Windows 11, version 25H2
Classification: Security Updates

File information

For a list of the files that are provided in this update, download the file information for cumulative update.

Prerequisites​

To apply this update, you must have .NET Framework 3.5 or 4.8.1 installed.

Restart requirement​

You must restart the computer after you apply this update if any affected files are being used. We recommend that you exit all .NET Framework-based applications before you apply this update.


 Source:

October 14, 2025-KB5066128 Cumulative Update for .NET Framework 3.5 and 4.8.1 for Windows 11, version 25H2 - Microsoft Support

support.microsoft.com support.microsoft.com
devblogs.microsoft.com

.NET and .NET Framework October 2025 servicing releases updates - .NET Blog

A recap of the latest servicing updates for .NET and .NET Framework for October 2025.
devblogs.microsoft.com devblogs.microsoft.com
 
Last edited:
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Thanks, Shawn. Working hard as per normal. You are appreciated.
 

My Computers My Computers

System One System Two Other systems

  • At a glance

    Windows 11 Pro 25H2 Build 26200.8894Intel(R) Core(TM) i7-4770K CPU @ 3.50GHz32.0 GB of I forget and the box is in storage.Gigabyte nVidia GeForce GTX 1660 Super OC 6GB
    OS
    Windows 11 Pro 25H2 Build 26200.8894
    Computer type
    PC/Desktop
    Manufacturer/Model
    Sin-built 2013
    CPU
    Intel(R) Core(TM) i7-4770K CPU @ 3.50GHz
    Motherboard
    ASUS ROG Maximus VI Formula
    Memory
    32.0 GB of I forget and the box is in storage.
    Graphics Card(s)
    Gigabyte nVidia GeForce GTX 1660 Super OC 6GB
    Sound Card
    ROG SupremeFX Formula 8-Channel High Definition Audio
    Monitor(s) Displays
    5 x LG 25MS500-B - 1 x 24MK430H-B - 1 x Wacom Pro 22" Touch Screen Tablet
    Screen Resolution
    All over the place
    Hard Drives
    Too many to list. OS on Samsung 1TB 870 QVO SATA
    PSU
    Silverstone 1500
    Case
    NZXT Phantom 820 Full-Tower Case
    Cooling
    Noctua NH-D15 Elite Class Dual Tower CPU Cooler / 6 x EziDIY 120mm / 2 x Corsair 140mm somethings / 1 x 140mm Thermaltake something / 2 x 200mm Corsair.
    Keyboard
    Corsair K95 / Logitech diNovo Edge Wireless
    Mouse
    Logitech: G402 / G502 / Mx Masters / Mx Air Cordless
    Internet Speed
    2000/500Mbps
    Browser
    All sorts
    Antivirus
    Kaspersky Premium
    Other Info
    ㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
    TP-Link BE9300 WiFi 7 Bluetooth 5.4 (Archer TBE550E)
    TP-Link TX201 V1 2.5GB Lan

    Grandstream HT812 - VoIP
    ASUS DSL-AX82U - Mesh
    ASUS RT-AC68U - Mesh
    ASUS RT-BE88U Router

    Brother MFC-L2880DW Printer

    I’m on a horse.

  • At a glance

    Windows 11 Pro 25H2 Build 26200.8894 (Wifes)13th Generation Intel® Core™ i5-1340P Process...16GB LPDDR5-52001x Intel® Iris® Xe Graphics
    Operating System
    Windows 11 Pro 25H2 Build 26200.8894 (Wifes)
    Computer type
    Laptop
    Manufacturer/Model
    LENOVO Yoga 7 14IRL8 - Type 82YL
    CPU
    13th Generation Intel® Core™ i5-1340P Processor(Core™ i5-1340P)
    Memory
    16GB LPDDR5-5200
    Graphics card(s)
    1x Intel® Iris® Xe Graphics
    Sound Card
    Optimized with Dolby Atmos®
    Screen Resolution
    QHD 2880 x 1800 OLED
    Hard Drives
    M.2 512 GB SSD PCIe
    Mouse
    Logiteck MX Master 3S
    Internet Speed
    2000/500
    Antivirus
    Defender / Malwarebytes
    Other Info
    …still on a horse.


    Wireless Network: Wi-Fi 6E 2x2 AX; Bluetooth® 5.1 or above
    Ports: 1x 1 Novo button; 2 in 1 Audio Combo jack; Micro SD Card Reader; HDMI 1.4b; 2 x USB Type-C (TBT4)
    USB 3.2 Gen 2 DP 1.4a
    PD 3.0); 1 x USB 3.2 Gen1 Type A
    Camera
    1x 1080P FHD IR/RGB Hybrid with Privacy Shutter and Dual Array Microphone
    Graphics
    1x Intel® Iris® Xe Graphics
    Monitor
    14" WUXGA
    Form Factor
    Convertible Notebook
  • Windows 11 Pro 25H2 Build 26200.8894 (Wifes)

    Yoga 7 2-in-1 14IML9 - Type 83DJ

    Processor: Intel® Core™ Ultra 7 155H Processor(Core™ Ultra 7 155H)

    Memory: 32GB LPD5X-7467

    Hard Drive: 1 TB SSD PCIe

    Wireless Network: 1x Wi-Fi 6E 2x2 AX; Bluetooth® 5.1 or above

    Ports: 1 x HDMI 2.1 TMDS; 1 x Novo Button; 1 x Combo Audio Jack
    2 x USB-C (USB 4.0)
    1 x USB-A 3.2 Gen 1

    Camera: 1080P FHD IR Hybrid with Dual Microphone

    Graphics: Intel® Arc™ Graphics

    Monitor: 14" 2.8K

    ...Where's my horse?
Downloading...

1760486028660.webp
 

My Computer My Computer

At a glance

Windows 11Intel® Xeon® X5690 3.47GHz Six-CoreG.Skill PC3-12800 1600MHz 24GBNVIDIA GeForce GTX 1050
OS
Windows 11
Computer type
PC/Desktop
Manufacturer/Model
Asus/Custom Build
CPU
Intel® Xeon® X5690 3.47GHz Six-Core
Motherboard
Asus P6T Deluxe v2
Memory
G.Skill PC3-12800 1600MHz 24GB
Graphics Card(s)
NVIDIA GeForce GTX 1050
Sound Card
SoundMAX ADI AD2000B HD Audio
Monitor(s) Displays
Acer T232HL Touch Screen
Screen Resolution
1920 x 1080 @ 60Hz
Hard Drives
6 Crucial MX500 SSD 1TB each.
PSU
Thermaltake Toughpower Gold 850W
Case
Thermaltake Armor VA8000SWA
Cooling
Thermaltake Air Cooling System
Keyboard
Illuminated Multimedia LED Keyboard
Mouse
M16 Dual Mode Illuminated Mouse - Bluetooth / 2.4 GHz Mode
Internet Speed
800 Mbps
Browser
Edge / Opera / Vivaldi / Chrome / Firefox / Brave
Antivirus
Windows Defender Security
All good!

1760488737308.webp
 

My Computer My Computer

At a glance

Windows 11Intel® Xeon® X5690 3.47GHz Six-CoreG.Skill PC3-12800 1600MHz 24GBNVIDIA GeForce GTX 1050
OS
Windows 11
Computer type
PC/Desktop
Manufacturer/Model
Asus/Custom Build
CPU
Intel® Xeon® X5690 3.47GHz Six-Core
Motherboard
Asus P6T Deluxe v2
Memory
G.Skill PC3-12800 1600MHz 24GB
Graphics Card(s)
NVIDIA GeForce GTX 1050
Sound Card
SoundMAX ADI AD2000B HD Audio
Monitor(s) Displays
Acer T232HL Touch Screen
Screen Resolution
1920 x 1080 @ 60Hz
Hard Drives
6 Crucial MX500 SSD 1TB each.
PSU
Thermaltake Toughpower Gold 850W
Case
Thermaltake Armor VA8000SWA
Cooling
Thermaltake Air Cooling System
Keyboard
Illuminated Multimedia LED Keyboard
Mouse
M16 Dual Mode Illuminated Mouse - Bluetooth / 2.4 GHz Mode
Internet Speed
800 Mbps
Browser
Edge / Opera / Vivaldi / Chrome / Firefox / Brave
Antivirus
Windows Defender Security
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