On June 8th, 2021, this update was released to replace a previous update to address a “revocation server was offline” error that may occur during installation. If you've already installed a previous release of this update, no action is required. To obtain the latest version of these updates, see the "How to obtain and install the update" section of the individual update article. Links to each article are found in the "Additional information about this update" section of this article.
On April 13th, 2021, this update was released to replace a previous release of this update.
Microsoft .NET Framework 2.0 Microsoft .NET Framework 3.0 Microsoft .NET Framework 4.5.2 Microsoft .NET Framework 4.6
IMPORTANT Verify thatyou have installed the required updates listed in the How to get this update section before installing this update.
IMPORTANT WSUS scan cab files will continue to be available for Windows Server 2008 SP2. If you have a subset of devices running this operating system without ESU, they might show as non-compliant in your patch management and compliance toolsets.
IMPORTANT Customers who have purchased the Extended Security Update (ESU) for on-premises versions of this OS must follow the procedures in KB4522133 to continue receiving security updates after extended support ends on January 14, 2020. For more information on ESU and which editions are supported, see KB4497181.
IMPORTANT Starting in August, 2019, updates to .NET Framework 4.6 and above, for Windows Server 2008 SP2 require SHA-2 Code signing support. Please make sure that you have all the latest Windows Updates before applying this update to avoid installation issues. For more detailed information about SHA-2 code signing support updates, please see KB 4474419.
IMPORTANT All updates for .NET Framework 4.7.2, 4.7.1, 4.7, 4.6.2, 4.6.1, and 4.6 require that the d3dcompiler_47.dll update is installed. We recommend that you install the included d3dcompiler_47.dll update before you apply this update. For more information about the d3dcompiler_47.dll, see KB 4019990.
IMPORTANT If you install a language pack after you install this update, you must reinstall this update. Therefore, we recommend that you install any language packs that you need before you install this update. For more information, see Add language packs to Windows.
An information disclosure vulnerability exists when the .NET Framework improperly handles objects in memory. An attacker who successfully exploited the vulnerability could disclose contents of an affected system's memory. To exploit the vulnerability, an authenticated attacker would need to run a specially crafted application. The update addresses the vulnerability by correcting how the .NET Framework handles objects in memory.
To learn more about the vulnerabilities, go to the following Common Vulnerabilities and Exposures (CVE).
Known issues in some parts of this update
This update does not install, and it returns either or both of the following error messages:
This issue was corrected by the latest release of the affected parts in this update.
If you've already installed a previous release of the affected parts, no action is required.
Additional information about this update
The following articles contain additional information about this update as it relates to individual product versions.
4578979 Description of the Security Only Update for .NET Framework 2.0, 3.0 for Windows Server 2008 SP2 (KB4578979)
4578983 Description of the Security Only Update for .NET Framework 4.5.2 for Windows 7 SP1 and Windows Server 2008 R2 SP1 and Windows Server 2008 SP2 (KB4578983)
4578987 Description of the Security Only Update for .NET Framework 4.6 for Windows 7 SP1 and Windows Server 2008 R2 SP1 and Windows Server 2008 SP2 (KB4578987)