Security Only update for .NET Framework 3.5 SP1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, and 4.7.1 updates for Windows 8.1, RT 8.1, and Server 2012 R2 (KB 4099639)

Summary

This update resolves a vulnerability in Microsoft .NET Framework that could cause denial of service when .NET Framework and .NET core components process XML documents incorrectly. An attacker who has successfully exploited this vulnerability could cause a denial of service against a .NET Framework application. To learn more about this vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2018-0765.

Additionally, this update resolves a security feature bypass vulnerability in Windows that could allow an attacker to bypass Device Guard. An attacker who successfully exploits this vulnerability could circumvent a User Mode Code Integrity (UMCI) policy on the computer. To learn more about this vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2018-1039.

Important

• All updates for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 require update 2919355 to be installed. We recommend that you install update 2919355 on your Windows RT 8.1-based, Windows 8.1-based, or Windows Server 2012 R2-based computer so that you receive updates in the future.

• 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.

Additional information about this security update

The following articles contain additional information about this security update as it relates to individual product versions.

• 4095515 Description of the Security Only update for .NET Framework 3.5 SP1 for Windows 8.1 and Server 2012 R2 (KB 4095515)

• 4095517 Description of the Security Only update for .NET Framework 4.5.2 for Windows 8.1, RT 8.1, and Server 2012 R2 (KB 4095517)

• 4096236 Description of the Security Only update for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, and 4.7.1 for Windows 8.1, RT 8.1, and Server 2012 R2 (KB 4096236)

How to obtain help and support for this security update

• Help for installing updates: Windows Update FAQ

• Security solutions for IT professionals: TechNet Security Support and Troubleshooting

• Help for protecting your Windows-based products and services from viruses and malware: Microsoft Secure

• Local support according to your country: International Support