CVE-2026-62909: .NET Elevation of Privilege Vulnerability

Published Aug 6, 2026
·
Updated

.NET Elevation of Privilege Vulnerability

Other sources

Executive summary

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

A missing error check in .NET causes an improper ACL to be applied to a shared resource, resulting in local elevation of privilege.

Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/429

CVSS Details

- Version: 3.1 - Severity: Medium - Score: 6.7 - Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Weakness: CWE-252: Unchecked Return Value

Affected Platforms

- Platforms: Linux, macOS - 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.NETCore.App.Runtime.linux-arm | >= 10.0.0, <= 10.0.10 | 10.0.11 Microsoft.NETCore.App.Runtime.linux-arm64 | >= 10.0.0, <= 10.0.10 | 10.0.11 Microsoft.NETCore.App.Runtime.linux-musl-arm | >= 10.0.0, <= 10.0.10 | 10.0.11 Microsoft.NETCore.App.Runtime.linux-musl-arm64 | >= 10.0.0, <= 10.0.10 | 10.0.11 Microsoft.NETCore.App.Runtime.linux-musl-x64 | >= 10.0.0, <= 10.0.10 | 10.0.11 Microsoft.NETCore.App.Runtime.linux-x64 | >= 10.0.0, <= 10.0.10 | 10.0.11 Microsoft.NETCore.App.Runtime.osx-arm64 | >= 10.0.0, <= 10.0.10 | 10.0.11 Microsoft.NETCore.App.Runtime.osx-x64 | >= 10.0.0, <= 10.0.10 | 10.0.11

<a name=".NET 9"></a>.NET 9 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.NETCore.App.Runtime.linux-arm | >= 9.0.0, <= 9.0.18 | 9.0.19 Microsoft.NETCore.App.Runtime.linux-arm64 | >= 9.0.0, <= 9.0.18 | 9.0.19 Microsoft.NETCore.App.Runtime.linux-musl-arm | >= 9.0.0, <= 9.0.18 | 9.0.19 Microsoft.NETCore.App.Runtime.linux-musl-arm64 | >= 9.0.0, <= 9.0.18 | 9.0.19 Microsoft.NETCore.App.Runtime.linux-musl-x64 | >= 9.0.0, <= 9.0.18 | 9.0.19 Microsoft.NETCore.App.Runtime.linux-x64 | >= 9.0.0, <= 9.0.18 | 9.0.19 Microsoft.NETCore.App.Runtime.osx-arm64 | >= 9.0.0, <= 9.0.18 | 9.0.19 Microsoft.NETCore.App.Runtime.osx-x64 | >= 9.0.0, <= 9.0.18 | 9.0.19

<a name=".NET 8"></a>.NET 8 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.NETCore.App.Runtime.linux-arm | >= 8.0.0, <= 8.0.29 | 8.0.30 Microsoft.NETCore.App.Runtime.linux-arm64 | >= 8.0.0, <= 8.0.29 | 8.0.30 Microsoft.NETCore.App.Runtime.linux-musl-arm | >= 8.0.0, <= 8.0.29 | 8.0.30 Microsoft.NETCore.App.Runtime.linux-musl-arm64 | >= 8.0.0, <= 8.0.29 | 8.0.30 Microsoft.NETCore.App.Runtime.linux-musl-x64 | >= 8.0.0, <= 8.0.29 | 8.0.30 Microsoft.NETCore.App.Runtime.linux-x64 | >= 8.0.0, <= 8.0.29 | 8.0.30 Microsoft.NETCore.App.Runtime.osx-arm64 | >= 8.0.0, <= 8.0.29 | 8.0.30 Microsoft.NETCore.App.Runtime.osx-x64 | >= 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 a user's 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-2026-62909

Acknowledgements

Kevin Gosse

Revisions

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

— GitHub

Diagnostics IPC - Handle truncation error in ipctransportgetdefaultname (abstract UDS exposure via long TMPDIR)

Affects: 8.0, 9.0, 10.0

— Red Hat

Uncaught exception in .NET allows an authorized attacker to elevate privileges locally.

— Microsoft

Affected Software

43 affected componentsFixes available
nuget/Microsoft.NETCore.App.Runtime.osx-x64>=8.0.0<=8.0.29
8.0.30
nuget/Microsoft.NETCore.App.Runtime.osx-arm64>=8.0.0<=8.0.29
8.0.30
nuget/Microsoft.NETCore.App.Runtime.linux-x64>=8.0.0<=8.0.29
8.0.30
nuget/Microsoft.NETCore.App.Runtime.linux-musl-x64>=8.0.0<=8.0.29
8.0.30
nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm64>=8.0.0<=8.0.29
8.0.30
nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm>=8.0.0<=8.0.29
8.0.30
nuget/Microsoft.NETCore.App.Runtime.linux-arm64>=8.0.0<=8.0.29
8.0.30
nuget/Microsoft.NETCore.App.Runtime.linux-arm>=8.0.0<=8.0.29
8.0.30
nuget/Microsoft.NETCore.App.Runtime.osx-x64>=9.0.0<=9.0.18
9.0.19
nuget/Microsoft.NETCore.App.Runtime.osx-arm64>=9.0.0<=9.0.18
9.0.19
nuget/Microsoft.NETCore.App.Runtime.linux-x64>=9.0.0<=9.0.18
9.0.19
nuget/Microsoft.NETCore.App.Runtime.linux-musl-x64>=9.0.0<=9.0.18
9.0.19
nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm64>=9.0.0<=9.0.18
9.0.19
nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm>=9.0.0<=9.0.18
9.0.19
nuget/Microsoft.NETCore.App.Runtime.linux-arm64>=9.0.0<=9.0.18
9.0.19
nuget/Microsoft.NETCore.App.Runtime.linux-arm>=9.0.0<=9.0.18
9.0.19
nuget/Microsoft.NETCore.App.Runtime.osx-x64>=10.0.0<=10.0.10
10.0.11
nuget/Microsoft.NETCore.App.Runtime.osx-arm64>=10.0.0<=10.0.10
10.0.11
nuget/Microsoft.NETCore.App.Runtime.linux-x64>=10.0.0<=10.0.10
10.0.11
nuget/Microsoft.NETCore.App.Runtime.linux-musl-x64>=10.0.0<=10.0.10
10.0.11
nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm64>=10.0.0<=10.0.10
10.0.11
nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm>=10.0.0<=10.0.10
10.0.11
nuget/Microsoft.NETCore.App.Runtime.linux-arm64>=10.0.0<=10.0.10
10.0.11
nuget/Microsoft.NETCore.App.Runtime.linux-arm>=10.0.0<=10.0.10
10.0.11
Microsoft .NET 9.0 installed on Linux<9.0.19
9.0.19
Microsoft Visual Studio 2022=17.14
17.14.38
Microsoft .NET 9.0 installed on Windows<9.0.19
9.0.19
Microsoft .NET 8.0 installed on Windows<8.0.30
8.0.30
Microsoft .NET 10.0 installed on Mac OS<10.0.11
10.0.11
Microsoft .NET 9.0 installed on Mac OS<9.0.19
9.0.19
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 .NET 10.0 installed on Windows<10.0.11
10.0.11
Microsoft Visual Studio 2026=18.8
18.8.3
Microsoft .NET 8.0 installed on Mac OS<8.0.30
8.0.30
Microsoft Visual Studio 2022>=17.14.0<17.14.38
Microsoft Visual Studio 2026>=18.8.0<18.8.3
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
Any of the following
Apple macOS
Linux Linux kernel
Microsoft Windows

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

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

    Fixed in 8.0.30
  2. Upgrade

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

    Fixed in 8.0.30
  3. Upgrade

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

    Fixed in 8.0.30
  4. Upgrade

    Upgrade nuget/Microsoft.NETCore.App.Runtime.linux-musl-x64 to a version that resolves this vulnerability.

    Fixed in 8.0.30
  5. Upgrade

    Upgrade nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm64 to a version that resolves this vulnerability.

    Fixed in 8.0.30
  6. Upgrade

    Upgrade nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm to a version that resolves this vulnerability.

    Fixed in 8.0.30
  7. Upgrade

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

    Fixed in 8.0.30
  8. Upgrade

    Upgrade nuget/Microsoft.NETCore.App.Runtime.linux-arm to a version that resolves this vulnerability.

    Fixed in 8.0.30
  9. Upgrade

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

    Fixed in 9.0.19
  10. Upgrade

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

    Fixed in 9.0.19
  11. Upgrade

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

    Fixed in 9.0.19
  12. Upgrade

    Upgrade nuget/Microsoft.NETCore.App.Runtime.linux-musl-x64 to a version that resolves this vulnerability.

    Fixed in 9.0.19
  13. Upgrade

    Upgrade nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm64 to a version that resolves this vulnerability.

    Fixed in 9.0.19
  14. Upgrade

    Upgrade nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm to a version that resolves this vulnerability.

    Fixed in 9.0.19
  15. Upgrade

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

    Fixed in 9.0.19
  16. Upgrade

    Upgrade nuget/Microsoft.NETCore.App.Runtime.linux-arm to a version that resolves this vulnerability.

    Fixed in 9.0.19
  17. Upgrade

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

    Fixed in 10.0.11
  18. Upgrade

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

    Fixed in 10.0.11
  19. Upgrade

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

    Fixed in 10.0.11
  20. Upgrade

    Upgrade nuget/Microsoft.NETCore.App.Runtime.linux-musl-x64 to a version that resolves this vulnerability.

    Fixed in 10.0.11
  21. Upgrade

    Upgrade nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm64 to a version that resolves this vulnerability.

    Fixed in 10.0.11
  22. Upgrade

    Upgrade nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm to a version that resolves this vulnerability.

    Fixed in 10.0.11
  23. Upgrade

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

    Fixed in 10.0.11
  24. Upgrade

    Upgrade nuget/Microsoft.NETCore.App.Runtime.linux-arm to a version that resolves this vulnerability.

    Fixed in 10.0.11
  25. Upgrade

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

    Fixed in 9.0.19Patch KB5122105
  26. Upgrade

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

    Fixed in 17.14.38
  27. Upgrade

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

    Fixed in 8.0.30Patch KB5122104
  28. Upgrade

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

    Fixed in 10.0.11Patch KB5122106
  29. Upgrade

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

    Fixed in 18.8.3
  30. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-arm64 to a version that resolves this vulnerability.

    Fixed in 10.0.11Patch CVE-2026-62909
  31. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-arm64 to a version that resolves this vulnerability.

    Fixed in 8.0.30Patch CVE-2026-62909
  32. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-arm64 to a version that resolves this vulnerability.

    Fixed in 9.0.19Patch CVE-2026-62909
  33. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-arm to a version that resolves this vulnerability.

    Fixed in 10.0.11Patch CVE-2026-62909
  34. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-arm to a version that resolves this vulnerability.

    Fixed in 8.0.30Patch CVE-2026-62909
  35. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-arm to a version that resolves this vulnerability.

    Fixed in 9.0.19Patch CVE-2026-62909
  36. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm64 to a version that resolves this vulnerability.

    Fixed in 10.0.11Patch CVE-2026-62909
  37. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm64 to a version that resolves this vulnerability.

    Fixed in 8.0.30Patch CVE-2026-62909
  38. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm64 to a version that resolves this vulnerability.

    Fixed in 9.0.19Patch CVE-2026-62909
  39. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to a version that resolves this vulnerability.

    Fixed in 10.0.11Patch CVE-2026-62909
  40. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to a version that resolves this vulnerability.

    Fixed in 8.0.30Patch CVE-2026-62909
  41. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to a version that resolves this vulnerability.

    Fixed in 9.0.19Patch CVE-2026-62909
  42. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-musl-x64 to a version that resolves this vulnerability.

    Fixed in 10.0.11Patch CVE-2026-62909
  43. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-musl-x64 to a version that resolves this vulnerability.

    Fixed in 8.0.30Patch CVE-2026-62909
  44. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-musl-x64 to a version that resolves this vulnerability.

    Fixed in 9.0.19Patch CVE-2026-62909
  45. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-x64 to a version that resolves this vulnerability.

    Fixed in 10.0.11Patch CVE-2026-62909
  46. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-x64 to a version that resolves this vulnerability.

    Fixed in 8.0.30Patch CVE-2026-62909
  47. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.linux-x64 to a version that resolves this vulnerability.

    Fixed in 9.0.19Patch CVE-2026-62909
  48. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.osx-arm64 to a version that resolves this vulnerability.

    Fixed in 10.0.11Patch CVE-2026-62909
  49. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.osx-arm64 to a version that resolves this vulnerability.

    Fixed in 8.0.30Patch CVE-2026-62909
  50. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.osx-arm64 to a version that resolves this vulnerability.

    Fixed in 9.0.19Patch CVE-2026-62909
  51. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.osx-x64 to a version that resolves this vulnerability.

    Fixed in 10.0.11Patch CVE-2026-62909
  52. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.osx-x64 to a version that resolves this vulnerability.

    Fixed in 8.0.30Patch CVE-2026-62909
  53. Upgrade

    Upgrade Microsoft.NETCore.App.Runtime.osx-x64 to a version that resolves this vulnerability.

    Fixed in 9.0.19Patch CVE-2026-62909
  54. Operational

    After installing the updated .NET runtime or SDK, restart the affected apps so the update takes effect.

Event History

Aug 6, 2026
Data Sourced
via Red Hat·09:10 PM
DescriptionSeverityAffected Software
Aug 11, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·05:04 PM
Data Sourced
via MITRE·05:04 PM
DescriptionSeverity
Data Sourced
via NVD·05:18 PM
RemedyDescriptionSeverityWeaknessAffected Software
Advisory Published
via GitHub·07:04 PM
Data Sourced
via GitHub·07:04 PM
DescriptionSeverityWeaknessAffected Software
Aug 19, 2026
Data Sourced
via Debian·07:21 AM
DescriptionAffected Software
Data Sourced
via Launchpad·07:21 AM
Description
Aug 20, 2026
Data Sourced
via Ubuntu·07:20 AM
RemedyDescriptionSeverityAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-62909?

CVE-2026-62909 has a high severity rating of 7.8.

2

How do I fix CVE-2026-62909?

To fix CVE-2026-62909, update the affected .NET software to the latest version provided by Microsoft.

3

What systems are affected by CVE-2026-62909?

CVE-2026-62909 affects Microsoft .NET versions 8.0, 9.0, and 10.0 on Windows, Linux, and Mac OS.

4

What does CVE-2026-62909 exploit?

CVE-2026-62909 exploits an uncaught exception in .NET that allows an authorized attacker to elevate privileges locally.

5

Is CVE-2026-62909 being actively exploited?

As of the latest information, there are no reports indicating that CVE-2026-62909 is actively being exploited in the wild.

Company

Resources

Contact

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