Applies to:

Microsoft .NET Framework 4.8

Summary

Denial of service vulnerabilities exist when .NET Framework improperly handles objects in heap memory, or when .NET Framework and .NET Core improperly process RegEx strings.

To learn more about the vulnerabilities, go to the following Common Vulnerabilities and Exposures (CVE).

Important

  • All updates for Windows 8.1, Windows RT 8.1, and Windows Server 2012 R2 require that update KB 2919355 is installed. We recommend that you install update KB 2919355 on your Windows 8.1-based, Windows RT 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 update

For more information about this update as it relates to its particular Windows version(s), see the following article(s) in the Microsoft Knowledge Base:

  • 4499408 Security and Quality Rollup for .NET Framework 3.5, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows 8.1, RT 8.1, and Server 2012 R2 (KB4499408)

How to obtain and install the update

Method 1: Windows Update

This update is available through Windows Update. When you turn on automatic updating, this update will be downloaded and installed automatically. For more information about how to get security updates automatically, see Windows Update: FAQ.

Method 2: Microsoft Update Catalog

To get the standalone package for this update, go to the Microsoft Update Catalog.

Method 3: Windows Software Update Services (WSUS)

On your WSUS server, follow these steps:

  1. Select Start, select Administrative Tools, and then select Microsoft Windows Server Update Services 3.0.

  2. Expand ComputerName, and then select Action.

  3. Select Import Updates.

  4. WSUS opens a browser window in which you may be prompted to install an ActiveX control. You must install the ActiveX control to continue.

  5. After the ActiveX control is installed, you see the Microsoft Update Catalog screen. Type 4499408 into the Search box, and then select Search.

  6. Locate the .NET Framework packages that match the operating systems, languages, and processors in your environment. Select Add to add them to your basket.

  7. After you select all the packages that you require, select View Basket.

  8. To import the packages to your WSUS server, select Import.

  9. After the packages are imported, select Close to return to WSUS.

The updates are now available for installation through WSUS.

Update deployment information

For deployment details for this security update, go to the following article in the Microsoft Knowledge Base:

20190514 Security update deployment information: May 14, 2019

Update removal information

Note We do not recommend that you remove any security update. To remove this update, use the Programs and Features item in Control Panel.

Update restart information

This update does not require a system restart after you apply it unless files that are being updated are locked or are being used.

Update replacement information

This update replaces previously released updates 4487080 and 4487258.

File information

The English (United States) version of this software update installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.

Note: The MANIFEST files (.manifest) and MUM files (.mum) that are installed are not listed.

File information

File hash information

File name

SHA1 hash

SHA256 hash

Windows8.1-KB4495624-arm.msu

A67A1F3DB8C4529951E05998177F1B6FA8F719F6

98B9378D26822FBEA14FED3DB840B498D29E839929542D7E3F47B4023459C8FA

Windows8.1-KB4495624-x64.msu

FE8DBB4CBE783FEA427F0132969E9670802952A5

EF46BF22B6C8EAE934BD85181D84DF72D1C268BE575B3D87652947037828B92D

Windows8.1-KB4495624-x86.msu

FE2C34B4357CAB479E7336C6165ECA4D9F9E3DF2

6B6A8D627EF0EDAD9B385346E027113C911A8F81EB23BB05C2CF3396B8132568

For all supported x64-based versions

File name

File version

File size

Date

Time

mscorlib.dll

4.8.3801.0

5,436,968

09-Apr-2019

03:24

normidna.nlp

59,342

27-Sep-2018

20:42

normnfc.nlp

47,076

27-Sep-2018

20:42

normnfd.nlp

40,566

27-Sep-2018

20:42

normnfkc.nlp

67,808

27-Sep-2018

20:42

normnfkd.nlp

61,718

27-Sep-2018

20:42

clrjit.dll

4.8.3801.0

1,364,528

09-Apr-2019

03:24

clr.dll

4.8.3801.0

11,268,656

09-Apr-2019

03:24

compatjit.dll

4.8.3801.0

1,280,048

09-Apr-2019

03:24

mscordacwks.dll

4.8.3801.0

1,807,920

09-Apr-2019

03:24

mscordbi.dll

4.8.3801.0

1,660,976

09-Apr-2019

03:24

mscorlib.ni.dll

4.8.3801.0

23,073,696

09-Apr-2019

03:27

peverify.dll

4.8.3801.0

272,432

09-Apr-2019

03:24

sos.dll

4.8.3801.0

928,304

09-Apr-2019

03:24

system.dll

4.8.3801.0

3,558,304

09-Apr-2019

03:27

system.dll

4.8.3801.0

3,558,304

09-Apr-2019

03:27

mscorlib.dll

4.8.3801.0

5,676,288

09-Apr-2019

03:27

normidna.nlp

59,342

27-Sep-2018

20:42

normnfc.nlp

47,076

27-Sep-2018

20:42

normnfd.nlp

40,566

27-Sep-2018

20:42

normnfkc.nlp

67,808

27-Sep-2018

20:42

normnfkd.nlp

61,718

27-Sep-2018

20:42

clrjit.dll

4.8.3801.0

560,688

09-Apr-2019

03:27

clr.dll

4.8.3801.0

8,042,240

09-Apr-2019

03:27

mscordacwks.dll

4.8.3801.0

1,314,344

09-Apr-2019

03:27

mscordbi.dll

4.8.3801.0

1,195,056

09-Apr-2019

03:27

mscorlib.ni.dll

4.8.3801.0

21,035,936

09-Apr-2019

03:27

peverify.dll

4.8.3801.0

189,720

09-Apr-2019

03:27

sos.dll

4.8.3801.0

774,192

09-Apr-2019

03:27

For all supported x86-based versions

File name

File version

File size

Date

Time

system.dll

4.8.3801.0

3,558,304

09-Apr-2019

03:27

mscorlib.dll

4.8.3801.0

5,676,288

09-Apr-2019

03:27

normidna.nlp

59,342

27-Sep-2018

20:42

normnfc.nlp

47,076

27-Sep-2018

20:42

normnfd.nlp

40,566

27-Sep-2018

20:42

normnfkc.nlp

67,808

27-Sep-2018

20:42

normnfkd.nlp

61,718

27-Sep-2018

20:42

clrjit.dll

4.8.3801.0

560,688

09-Apr-2019

03:27

clr.dll

4.8.3801.0

8,042,240

09-Apr-2019

03:27

mscordacwks.dll

4.8.3801.0

1,314,344

09-Apr-2019

03:27

mscordbi.dll

4.8.3801.0

1,195,056

09-Apr-2019

03:27

mscorlib.ni.dll

4.8.3801.0

21,035,936

09-Apr-2019

03:27

peverify.dll

4.8.3801.0

189,720

09-Apr-2019

03:27

sos.dll

4.8.3801.0

774,192

09-Apr-2019

03:27

For all supported arm-based versions

File name

File version

File size

Date

Time

mscorlib.dll

4.8.3801.0

5,677,824

09-Apr-2019

03:21

normidna.nlp

59,342

27-Sep-2018

20:42

normnfc.nlp

47,076

27-Sep-2018

20:42

normnfd.nlp

40,566

27-Sep-2018

20:42

normnfkc.nlp

67,808

27-Sep-2018

20:42

normnfkd.nlp

61,718

27-Sep-2018

20:42

clrjit.dll

4.8.3801.0

687,352

09-Apr-2019

03:21

clr.dll

4.8.3801.0

7,478,016

09-Apr-2019

03:21

mscordacwks.dll

4.8.3801.0

1,358,592

09-Apr-2019

03:21

mscordbi.dll

4.8.3801.0

1,213,096

09-Apr-2019

03:21

mscorlib.ni.dll

4.8.3801.0

22,692,256

09-Apr-2019

03:27

sos.dll

4.8.3801.0

684,800

09-Apr-2019

03:21

system.dll

4.8.3801.0

3,558,304

09-Apr-2019

03:27

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