CVE-2026-70354: .NET Core Remote Code Execution Vulnerability

Published Aug 11, 2026
·
Updated

.NET Core Remote Code Execution Vulnerability

Other sources

Executive summary

Microsoft is releasing this security advisory to provide information about a vulnerability in Windows Presentation Foundation. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

An out-of-bounds write in .NET allows an unauthorized attacker to execute code locally.

Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/432

CVSS Details

- Version: 3.1 - Severity: High - Score: 7.8 - Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Weakness: CWE-787: Out-of-bounds Write

Affected Platforms

- Platforms: Windows - Architectures: All

<a name="affected-packages"></a>Affected Packages The vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below

<a name=".NET 10"></a>.NET 10 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.WindowsDesktop.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.10 | 10.0.11 Microsoft.WindowsDesktop.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.10 | 10.0.11 Microsoft.WindowsDesktop.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.10 | 10.0.11

<a name=".NET 9"></a>.NET 9 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.WindowsDesktop.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.18 | 9.0.19 Microsoft.WindowsDesktop.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.18 | 9.0.19 Microsoft.WindowsDesktop.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.18 | 9.0.19

<a name=".NET 8"></a>.NET 8 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.WindowsDesktop.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.29 | 8.0.30 Microsoft.WindowsDesktop.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.29 | 8.0.30 Microsoft.WindowsDesktop.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.29 | 8.0.30

Advisory FAQ

<a name="how-affected"></a>How do I know if I am affected?

If using a package listed in affected packages, an application is exposed to the vulnerability.

<a name="how-fix"></a>How do I fix the issue?

1. To fix the issue please install the latest version of .NET. If users have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt them to update Visual Studio, which will also update their .NET SDKs. 2. If an application references the vulnerable package, update the package reference to the patched version. Users can list the versions they have installed by running the dotnet --info command.

Once users have installed the updated runtime or SDK, they should restart their apps for the update to take effect.

Additionally, if they've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.

Other Information

Reporting Security Issues

If users have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ.

Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty.

Support

Users can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. Users can ask questions in the linked discussion issue.

Disclaimer

The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

External Links

CVE-2026-70354

Revisions

V1.0 (08/11/2026): Advisory published.

— GitHub

Affected Software

106 affected componentsFixes available
Microsoft .NET Framework=3.5, =4.6.2, =4.7, =4.7.1, =4.7.2
2.0.50727.8984 & 3.0.30729.8980 & 4.7.4144.0
Microsoft .NET Framework=3.5
2.0.50727.8984 & 3.0.30729.8980
Microsoft .NET Framework=3.5
2.0.50727.8984 & 3.0.30729.8980
Microsoft .NET Framework=4.8.1
4.8.9344.0
Microsoft .NET Framework=3.5
2.0.50727.9183 & 3.0.30729.9169
Microsoft .NET Framework=4.8
4.8.4805.0
Microsoft .NET Framework=4.6.2, =4.7, =4.7.1, =4.7.2
4.7.4144.0
Microsoft .NET Framework=3.5, =4.8.1
2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0
Microsoft .NET Framework=3.5, =4.8.1
2.0.50727.9183 & 3.0.30729.9169 & 4.8.9344.0
Microsoft .NET Framework=3.5, =4.8.1
2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0
Microsoft .NET 9.0 installed on Linux<9.0.19
9.0.19
Microsoft .NET 9.0 installed on Mac OS<9.0.19
9.0.19
Microsoft .NET 8.0 installed on Windows<8.0.30
8.0.30
Microsoft .NET Framework=3.5, =4.7.2
2.0.50727.9070 & 3.0.30729.9068 & 4.7.4144.0
Microsoft .NET 8.0 installed on Mac OS<8.0.30
8.0.30
Microsoft .NET Framework=3.5, =4.8
2.0.50727.9070 & 3.0.30729.9068 & 4.8.4805.0
Microsoft .NET 9.0 installed on Windows<9.0.19
9.0.19
Microsoft .NET 10.0 installed on Windows<10.0.11
10.0.11
Microsoft .NET 8.0 installed on Linux<8.0.30
8.0.30
Microsoft .NET 10.0 installed on Linux<10.0.11
10.0.11
Microsoft Visual Studio 2022=17.14
17.14.38
Microsoft Visual Studio 2026=18.8
18.8.3
Microsoft .NET Framework=4.8
4.8.4805.0
Microsoft .NET Framework=4.8
4.8.4805.0
Microsoft .NET 10.0 installed on Mac OS<10.0.11
10.0.11
Microsoft .NET Framework=3.5, =4.8.1
2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0
Microsoft .NET Framework=4.6.2, =4.7, =4.7.1, =4.7.2
4.7.4144.0
Microsoft .NET Framework=3.5, =4.8
2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0
nuget/Microsoft.WindowsDesktop.App.Runtime.win-x86>=8.0.0<=8.0.29
8.0.30
nuget/Microsoft.WindowsDesktop.App.Runtime.win-x64>=8.0.0<=8.0.29
8.0.30
nuget/Microsoft.WindowsDesktop.App.Runtime.win-arm64>=8.0.0<=8.0.29
8.0.30
nuget/Microsoft.WindowsDesktop.App.Runtime.win-x86>=9.0.0<=9.0.18
9.0.19
nuget/Microsoft.WindowsDesktop.App.Runtime.win-x64>=9.0.0<=9.0.18
9.0.19
nuget/Microsoft.WindowsDesktop.App.Runtime.win-arm64>=9.0.0<=9.0.18
9.0.19
nuget/Microsoft.WindowsDesktop.App.Runtime.win-x86>=10.0.0<=10.0.10
10.0.11
nuget/Microsoft.WindowsDesktop.App.Runtime.win-x64>=10.0.0<=10.0.10
10.0.11
nuget/Microsoft.WindowsDesktop.App.Runtime.win-arm64>=10.0.0<=10.0.10
10.0.11
Microsoft Visual Studio 2022>=17.14.0<17.14.38
Microsoft Visual Studio 2026>=18.8.0<18.8.3
All of the following
Microsoft .NET Framework=4.8.1
Any of the following
Microsoft Windows 11 26h1
Microsoft Windows 11 26h1
All of the following
Microsoft .NET Framework=4.8
Any of the following
Microsoft Windows 10 1607
Microsoft Windows 10 1607
Microsoft Windows Server 2012
Microsoft Windows Server 2012=r2
Microsoft Windows Server 2016
All of the following
Any of the following
Microsoft .NET Framework=4.6.2
Microsoft .NET Framework=4.7
Microsoft .NET Framework=4.7.1
Microsoft .NET Framework=4.7.2
Any of the following
Microsoft Windows Server 2012
Microsoft Windows Server 2012=r2
All of the following
Any of the following
Microsoft .NET Framework=3.5
Microsoft .NET Framework=4.7.2
Any of the following
Microsoft Windows 10 1809
Microsoft Windows 10 1809
Microsoft Windows 10 1809
Microsoft Windows Server 2019
All of the following
Any of the following
Microsoft .NET Framework=3.5
Microsoft .NET Framework=4.8.1
Any of the following
Microsoft Windows 10 21h2
Microsoft Windows 10 21h2
Microsoft Windows 10 21h2
Microsoft Windows 10 22h2
Microsoft Windows 10 22h2
Microsoft Windows 10 22h2
Microsoft Windows 11 23h2
Microsoft Windows 11 23h2
Microsoft Windows 11 24h2
Microsoft Windows 11 24h2
Microsoft Windows 11 25h2
Microsoft Windows 11 25h2
Microsoft Windows Server 2022
Microsoft Windows Server 2025
All of the following
Any of the following
Microsoft .NET Framework=3.5
Microsoft .NET Framework=4.8
Any of the following
Microsoft Windows 10 1809
Microsoft Windows 10 1809
Microsoft Windows 10 1809
Microsoft Windows 10 21h2
Microsoft Windows 10 21h2
Microsoft Windows 10 21h2
Microsoft Windows 10 22h2
Microsoft Windows 10 22h2
Microsoft Windows 10 22h2
Microsoft Windows Server 2019
Microsoft Windows Server 2022
All of the following
Any of the following
Microsoft .NET Framework=3.5
Microsoft .NET Framework=4.6.2
Microsoft .NET Framework=4.7
Microsoft .NET Framework=4.7.1
Microsoft .NET Framework=4.7.2
Any of the following
Microsoft Windows 10 1607
Microsoft Windows 10 1607
Microsoft Windows Server 2016
All of the following
Microsoft .NET Framework=3.5
Any of the following
Microsoft Windows 11 26h1
Microsoft Windows 11 26h1
Microsoft Windows Server 2012
Microsoft Windows Server 2012=r2
All of the following
Any of the following
Microsoft .NET>=8.0.0<8.0.30
Microsoft .NET>=9.0.0<9.0.19
Microsoft .NET>=10.0.0<10.0.11
Microsoft Windows

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.8984 & 3.0.30729.8980 & 4.7.4144.0Patch KB5120418
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.8984 & 3.0.30729.8980Patch KB5120716
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.8984 & 3.0.30729.8980Patch KB5120695
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 4.8.9344.0Patch KB5120711
  5. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9183 & 3.0.30729.9169Patch KB5120747
  6. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 4.8.4805.0Patch KB5120706
  7. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 4.7.4144.0Patch KB5120699
  8. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0Patch KB5120713
  9. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9344.0Patch KB5120708
  10. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0Patch KB5120710
  11. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 9.0.19Patch KB5122105
  12. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 8.0.30Patch KB5122104
  13. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9070 & 3.0.30729.9068 & 4.7.4144.0Patch KB5120698
  14. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9070 & 3.0.30729.9068 & 4.8.4805.0Patch KB5120703
  15. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.11Patch KB5122106
  16. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 17.14.38
  17. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 18.8.3
  18. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 4.8.4805.0Patch KB5120702
  19. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 4.8.4805.0Patch KB5120704
  20. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0Patch KB5120709
  21. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 4.7.4144.0Patch KB5120700
  22. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0Patch KB5120714
  23. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0Patch KB5120701
  24. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0Patch KB5120705
  25. Upgrade

    Upgrade nuget/Microsoft.WindowsDesktop.App.Runtime.win-x86 to a version that resolves this vulnerability.

    Fixed in 8.0.30
  26. Upgrade

    Upgrade nuget/Microsoft.WindowsDesktop.App.Runtime.win-x64 to a version that resolves this vulnerability.

    Fixed in 8.0.30
  27. Upgrade

    Upgrade nuget/Microsoft.WindowsDesktop.App.Runtime.win-arm64 to a version that resolves this vulnerability.

    Fixed in 8.0.30
  28. Upgrade

    Upgrade nuget/Microsoft.WindowsDesktop.App.Runtime.win-x86 to a version that resolves this vulnerability.

    Fixed in 9.0.19
  29. Upgrade

    Upgrade nuget/Microsoft.WindowsDesktop.App.Runtime.win-x64 to a version that resolves this vulnerability.

    Fixed in 9.0.19
  30. Upgrade

    Upgrade nuget/Microsoft.WindowsDesktop.App.Runtime.win-arm64 to a version that resolves this vulnerability.

    Fixed in 9.0.19
  31. Upgrade

    Upgrade nuget/Microsoft.WindowsDesktop.App.Runtime.win-x86 to a version that resolves this vulnerability.

    Fixed in 10.0.11
  32. Upgrade

    Upgrade nuget/Microsoft.WindowsDesktop.App.Runtime.win-x64 to a version that resolves this vulnerability.

    Fixed in 10.0.11
  33. Upgrade

    Upgrade nuget/Microsoft.WindowsDesktop.App.Runtime.win-arm64 to a version that resolves this vulnerability.

    Fixed in 10.0.11
  34. Upgrade

    Upgrade Microsoft.WindowsDesktop.App.Runtime.win-arm64 to a version that resolves this vulnerability.

    Fixed in 10.0.11
  35. Upgrade

    Upgrade Microsoft.WindowsDesktop.App.Runtime.win-arm64 to a version that resolves this vulnerability.

    Fixed in 8.0.30
  36. Upgrade

    Upgrade Microsoft.WindowsDesktop.App.Runtime.win-arm64 to a version that resolves this vulnerability.

    Fixed in 9.0.19
  37. Upgrade

    Upgrade Microsoft.WindowsDesktop.App.Runtime.win-x64 to a version that resolves this vulnerability.

    Fixed in 10.0.11
  38. Upgrade

    Upgrade Microsoft.WindowsDesktop.App.Runtime.win-x64 to a version that resolves this vulnerability.

    Fixed in 8.0.30
  39. Upgrade

    Upgrade Microsoft.WindowsDesktop.App.Runtime.win-x64 to a version that resolves this vulnerability.

    Fixed in 9.0.19
  40. Upgrade

    Upgrade Microsoft.WindowsDesktop.App.Runtime.win-x86 to a version that resolves this vulnerability.

    Fixed in 10.0.11
  41. Upgrade

    Upgrade Microsoft.WindowsDesktop.App.Runtime.win-x86 to a version that resolves this vulnerability.

    Fixed in 8.0.30
  42. Upgrade

    Upgrade Microsoft.WindowsDesktop.App.Runtime.win-x86 to a version that resolves this vulnerability.

    Fixed in 9.0.19
  43. Operational

    After installing the updated .NET runtime or SDK, restart your apps for the update to take effect.

  44. Operational

    For self-contained applications targeting any impacted .NET versions, recompile and redeploy the applications after installing the patched .NET runtime/SDK.

Event History

Aug 11, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·05:07 PM
Data Sourced
via MITRE·05:07 PM
DescriptionSeverity
Data Sourced
via NVD·05:19 PM
RemedyDescriptionSeverityWeaknessAffected Software
Advisory Published
via GitHub·07:24 PM
Data Sourced
via GitHub·07:24 PM
DescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-70354?

CVE-2026-70354 has a high severity rating of 7.8.

2

How do I fix CVE-2026-70354?

To fix CVE-2026-70354, apply the latest security updates for the affected .NET versions provided by Microsoft.

3

What software is affected by CVE-2026-70354?

CVE-2026-70354 affects Microsoft .NET 8.0, 9.0, and 10.0 across various operating systems including Windows, Mac OS, and Linux.

4

What type of vulnerability is CVE-2026-70354?

CVE-2026-70354 is a remote code execution vulnerability due to an out-of-bounds write in .NET.

5

Who can exploit CVE-2026-70354?

An unauthorized attacker can exploit CVE-2026-70354 to execute code locally on vulnerable systems.

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203