It’s time to patch Windows 10 again as April’s Patch Tuesday has arrived. Microsoft has released cumulative update KB4549951 for Windows 10 Version 1909 and 1903 which will take the complete build of your OS to 1903-OS Build 18362.778 and 1909-OS Build 18363.778.
Unlike the previously released cumulative update, this update is mandatory and will be installed on your system by default. If you have not installed any of the previous updates, this update will install them for you.
Quick Facts about KB4549951
- Release date: 14th April 2020
- Operating Systems Support: Windows 10 Version 1909, Windows 10 Version 1903
- Build no. after installing KB4549951: 1903-OS Build 18362.778 and 1909-OS Build 18363.778
What’s new in KB4549951 update
This update comes with three critical zero-day fixes to Windows 10 OS. A total of 113 vulnerabilities have been fixed in Microsoft products which includes 15 critical, 93 important, 3 moderate and 2 low level vulnerabilities.
Here is the list of security improvements from knowledgebase released by Microsoft.
- Addresses an issue that prevents certain apps from being installed if they are published using a Group Policy Object.
- Addresses an issue that prevents a wired network interface from obtaining a new Dynamic Host Configuration Protocol (DHCP) IP address on new subnets and virtual LANs (VLAN) after wired 802.1x re-authentication. The issue occurs if you use VLANs that are based on accounts and a VLAN change occurs after a user signs in.
- Security updates to Microsoft Scripting Engine, Windows App Platform, Frameworks, Windows Cloud Infrastructure, Windows Virtualization, Microsoft Graphics Component, Windows Kernel, Windows Media, Windows Shell, Windows Management, Windows Fundamentals, Windows Virtualization, Windows Storage, Filesystems, Windows Update Stack, and the Microsoft JET Database Engine.
And here is the breakdown of each vulnerability fix with respect to the Microsoft product:
| Product | CVE |
| Windows Defender | CVE-2020-0835, CVE-2020-1002 |
| Windows Update | CVE-2020-0985, CVE-2020-0996, CVE-2020-0983, CVE-2020-1014 |
| Windows | CVE-2020-0794, CVE-2020-0944, CVE-2020-1001, CVE-2020-1006, CVE-2020-1029, CVE-2020-0934, CVE-2020-0940, CVE-2020-0942, CVE-2020-0965, CVE-2020-0981, CVE-2020-1009, CVE-2020-1011, CVE-2020-1016, CVE-2020-1017, CVE-2020-1094 |
| Windows Kernel | CVE-2020-0913, CVE-2020-0955, CVE-2020-1000, CVE-2020-1003, CVE-2020-1007, CVE-2020-1027, CVE-2020-0699, CVE-2020-0821, CVE-2020-0888, CVE-2020-0936, CVE-2020-0956, CVE-2020-0957, CVE-2020-0962, CVE-2020-1015 |
| Windows DNS | CVE-2020-0993 |
| Remote Desktop Client | CVE-2020-0919 |
| Windows Media | CVE-2020-0945, CVE-2020-0946, CVE-2020-0947, CVE-2020-0948, CVE-2020-0949, CVE-2020-0950, CVE-2020-0937, CVE-2020-0939 |
If you want more information about each vulnerability, you can go through Microsoft Security Update April release notes.
Of all the vulnerabilities, the following vulnerabilities are the most critical. This update must be installed if you are using any Adobe product on your system.
- CVE-2020-0935 – OneDrive for Windows Elevation of Privilege Vulnerability
- CVE-2020-1020 – Adobe Font Manager Library Remote Code Execution Vulnerability
- CVE-2020-0938 and CVE-2020-1020 – Adobe Font Manager Library Remote Code Execution Vulnerability
Install KB4549951 using Windows Update
To install this update using Windows Update, please go to Windows Settings –> Update & Security –> Windows Update. In the right-hand pane, click on the Check for updates button.
You will see the following under Optional updates available:
2020-04 Cumulative Update for Windows 10 Version 1909 for x64-based Systems (KB4549951)
Since this is a mandatory update, it will download and install automatically. Once installed, you will need to restart the system for the changes to take effect.
Download KB4549951 Offline installers
You can also download this cumulative update and then install it on any system without requiring any Internet connection.
Download KB4549951 for Windows 10 Version 1909 32-bit [193.1 MB]
Download KB4549951 for Windows 10 Version 1909 64-bit [358 MB]
Download KB4549951 for Windows 10 Version 1903 32-bit [193.1 MB]
Download KB4549951 for Windows 10 Version 1903 64-bit [358 MB]
To install the update, simply run the downloaded MSU file and Windows will automatically install the cumulative update. After installing this update, the Operating System build number will be 18363.778 for Windows 10 Version 1909 and 18362.778 for Windows 10 Version 1903.
You can check your current Windows build by going to Run –> winver.
Uninstall KB4554364 cumulative update
At the time of this writing, I did not find any problem being discussed in different forums regarding this update.
However, if you are having issues with this update, it can be uninstalled in two ways:
Uninstall KB4549951 using Windows Update History tool
- Go to Windows Settings (Windows key + i) –> Update & Security –> Windows Updatestrong>.
- From the right-hand pane, click on View Update History.
- Now click on Uninstall updates.
- Select Update for Microsoft Windows (KB4549951) and press the Uninstall button.
Uninstall KB4549951 using command-line
Another quick way to uninstall this update is by using the command prompt. Here are the commands:
- Open Command Prompt (Run –> cmd)
- Run the following command:
wmic qfe list brief /format:table - This will show all the updates installed on the computer. Make sure KB4549951 is on the list.
- To uninstall the update, run the following command
wusa /uninstall /kb:4549951
The system needs to be restarted after uninstalling the update.
Similar fixes are also available for earlier versions of Windows. You can go through them here:
| Windows 10 Version 1809 | KB4549949 (OS Build 17763.1158) | Download |
| Windows 10 Version 1803 | KB4550922 (OS Build 17134.1425) | Download |
| Windows 10 Version 1709 | KB4550927 (OS Build 16299.1806) | Download |
| Windows 10 Version 1703 | KB4550939 (OS Build 15063.2346) | Download |
| Windows 10 Version 1607 | KB4550929 (OS Build 14393.3630) | Download |
| Windows 10 Version 1507 | KB4550930 (OS Build 10240.18545) | Download |
