.NET Elevation of Privilege Vulnerability

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

Improper input validation in .NET allows an unauthorized attacker to elevate privileges locally.

Source published

12 May 2026 16:58:34 UTC

Source modified

10 Aug 2026 15:14:00 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 7.3 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L/E:U/RL:O/RC:C

Improper input validation in .NET allows an unauthorized attacker to elevate privileges locally.

Source published

May 12, 2026, 4:58:34 PM (timezone not stated)

Source modified

Aug 10, 2026, 3:14:00 PM (timezone not stated)

Observed here

7 Nov 2026 08:31:23 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 7.3 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L/E:U/RL:O/RC:C

Improper input validation in .NET allows an unauthorized attacker to elevate privileges locally.

Source published

12 May 2026 18:17:13 UTC

Source modified

26 Oct 2026 18:10:00 UTC

Observed here

27 Oct 2026 09:03:12 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 7.3 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L

CVSS 3.1 · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c · Secondary · 7.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L

## Executive Summary: Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 8.0, .NET 9.0, and .NET 10.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. Improper input validation in .NET allows an unauthorized attacker to elevate privileges locally. ## Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/398 ## CVSS Details - **Version:** 3.1 - **Severity:** High - **Score:** 7.3 - **Vector:** AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L/E:U/RL:O/RC:C - **Weakness:** CWE-122: Heap-based Buffer Overflow, CWE-20: Improper Input Validation ## 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](https://www.nuget.org/packages/Microsoft.WindowsDesktop.App.Runtime.win-arm64) | >= 10.0.0, <= 10.0.7 | 10.0.8 [Microsoft.WindowsDesktop.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.WindowsDesktop.App.Runtime.win-x64) | >= 10.0.0, <= 10.0.7 | 10.0.8 [Microsoft.WindowsDesktop.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.WindowsDesktop.App.Runtime.win-x86) | >= 10.0.0, <= 10.0.7 | 10.0.8 ### <a name=".NET 9"></a>.NET 9 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- [Microsoft.WindowsDesktop.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.WindowsDesktop.App.Runtime.win-arm64) | >= 9.0.0, <= 9.0.15 | 9.0.16 [MMicrosoft.WindowsDesktop.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.WindowsDesktop.App.Runtime.win-x64) | >= 9.0.0, <= 9.0.15 | 9.0.16 [Microsoft.WindowsDesktop.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.WindowsDesktop.App.Runtime.win-x86) | >= 9.0.0, <= 9.0.15 | 9.0.16 ### <a name=".NET 8"></a>.NET 8 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- [Microsoft.WindowsDesktop.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.WindowsDesktop.App.Runtime.win-arm64) | >= 8.0.0, <= 8.0.26 | 8.0.27 [MMicrosoft.WindowsDesktop.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.WindowsDesktop.App.Runtime.win-x64) | >= 8.0.0, <= 8.0.26 | 8.0.27 [Microsoft.WindowsDesktop.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.WindowsDesktop.App.Runtime.win-x86) | >= 8.0.0, <= 8.0.26 | 8.0.27 ## Advisory FAQ ### <a name="how-affected"></a>How do I know if I am affected? If using a package listed in [affected packages](#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 8.0, NET 9.0, or .NET 10.0, as appropriate. If developers have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt them to update Visual Studio, which will also update the applications's .NET SDKs. 2. If a developer's application references the vulnerable package, update the package reference to the patched version. Developers can list the versions they have installed by running the `dotnet --info` command. Once developers have installed the updated runtime or SDK, they can restart the app for the update to take effect. Additionally, if developers have deployed [self-contained applications](https://docs.microsoft.com/dotnet/core/deploying/#self-contained-deployments-scd) targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. ## Other Information ### Reporting Security Issues A potential security issue has been found in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the [MSRC Researcher Portal](https://msrc.microsoft.com/report/vulnerability/new). Further information can be found in the MSRC [Report an Issue FAQ](https://www.microsoft.com/msrc/faqs-report-an-issue). 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 Questions about this issue can be submitted to 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. Questions should be submitted thorugh 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-2026-35433]( https://www.cve.org/CVERecord?id=CVE-2026-35433) ### Acknowledgements Ky0toFu ### Revisions V1.0 (May 12, 2026): Advisory published.

Source published

18 May 2026 19:20:19 UTC

Source modified

8 Jul 2026 17:45:16 UTC

Observed here

23 Oct 2026 16:01:25 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L

Publisher rating · HIGH