high · 7.8 Patched

Microsoft Security Advisory CVE-2026-96231 - .NET and Visual Studio Elevation of Privilege Vulnerability

CVE-2026-96231 · GHSA-2j93-m82w-73j2 · published 13 Oct 2026

How serious is it

  • Severity: high, CVSS score 7.8 out of 10.
  • No exploit prediction (EPSS) score yet.
  • Not on the CISA list of exploited vulnerabilities.
  • No public exploit in Exploit-DB.

Is your app affected by CVE-2026-96231?

Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.

Who is affected

  • Microsoft.NETCore.App.Runtime.linux-arm (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.NETCore.App.Runtime.linux-arm64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.NETCore.App.Runtime.linux-musl-arm (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.NETCore.App.Runtime.linux-musl-arm64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.NETCore.App.Runtime.linux-musl-x64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.NETCore.App.Runtime.linux-x64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.NETCore.App.Runtime.osx-arm64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.NETCore.App.Runtime.osx-x64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.NETCore.App.Runtime.linux-arm (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.NETCore.App.Runtime.linux-arm64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.NETCore.App.Runtime.linux-musl-arm (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.NETCore.App.Runtime.linux-musl-arm64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.NETCore.App.Runtime.linux-musl-x64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.NETCore.App.Runtime.linux-x64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.NETCore.App.Runtime.osx-arm64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.NETCore.App.Runtime.osx-x64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.NETCore.App.Runtime.linux-arm (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.NETCore.App.Runtime.linux-arm64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.NETCore.App.Runtime.linux-musl-arm (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.NETCore.App.Runtime.linux-musl-arm64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.NETCore.App.Runtime.linux-musl-x64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.NETCore.App.Runtime.linux-x64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.NETCore.App.Runtime.osx-arm64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.NETCore.App.Runtime.osx-x64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.NETCore.App.Runtime.linux-arm (NuGet) >= 11.0.0-preview.1, <= 11.0.0-rc.1
  • Microsoft.NETCore.App.Runtime.linux-arm64 (NuGet) >= 11.0.0-preview.1, <= 11.0.0-rc.1
  • Microsoft.NETCore.App.Runtime.linux-musl-arm (NuGet) >= 11.0.0-preview.1, <= 11.0.0-rc.1
  • Microsoft.NETCore.App.Runtime.linux-musl-arm64 (NuGet) >= 11.0.0-preview.1, <= 11.0.0-rc.1
  • Microsoft.NETCore.App.Runtime.linux-musl-x64 (NuGet) >= 11.0.0-preview.1, <= 11.0.0-rc.1
  • Microsoft.NETCore.App.Runtime.linux-x64 (NuGet) >= 11.0.0-preview.1, <= 11.0.0-rc.1
  • Microsoft.NETCore.App.Runtime.osx-arm64 (NuGet) >= 11.0.0-preview.1, <= 11.0.0-rc.1
  • Microsoft.NETCore.App.Runtime.osx-x64 (NuGet) >= 11.0.0-preview.1, <= 11.0.0-rc.1

How to check

  1. Look for Microsoft.NETCore.App.Runtime.linux-arm in your lockfile and compare its version with the range above.
  2. Look for Microsoft.NETCore.App.Runtime.linux-arm64 in your lockfile and compare its version with the range above.
  3. Look for Microsoft.NETCore.App.Runtime.linux-musl-arm in your lockfile and compare its version with the range above.
  4. Look for Microsoft.NETCore.App.Runtime.linux-musl-arm64 in your lockfile and compare its version with the range above.
  5. Look for Microsoft.NETCore.App.Runtime.linux-musl-x64 in your lockfile and compare its version with the range above.
  6. Look for Microsoft.NETCore.App.Runtime.linux-x64 in your lockfile and compare its version with the range above.
  7. Look for Microsoft.NETCore.App.Runtime.osx-arm64 in your lockfile and compare its version with the range above.
  8. Look for Microsoft.NETCore.App.Runtime.osx-x64 in your lockfile and compare its version with the range above.
  9. Or paste your lockfile into the checker: it lists every package with a known vulnerability, this one included.

How to fix

Copies a prompt for Claude Code, Cursor or Codex: it checks your lockfiles for this and upgrades it.
  1. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.NETCore.App.Runtime.linux-arm to 8.0.32 or later, commit the lockfile and redeploy.
  2. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.NETCore.App.Runtime.linux-arm64 to 8.0.32 or later, commit the lockfile and redeploy.
  3. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to 8.0.32 or later, commit the lockfile and redeploy.
  4. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm64 to 8.0.32 or later, commit the lockfile and redeploy.
  5. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.NETCore.App.Runtime.linux-musl-x64 to 8.0.32 or later, commit the lockfile and redeploy.
  6. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.NETCore.App.Runtime.linux-x64 to 8.0.32 or later, commit the lockfile and redeploy.
  7. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.NETCore.App.Runtime.osx-arm64 to 8.0.32 or later, commit the lockfile and redeploy.
  8. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.NETCore.App.Runtime.osx-x64 to 8.0.32 or later, commit the lockfile and redeploy.
  9. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.NETCore.App.Runtime.linux-arm to 10.0.13 or later, commit the lockfile and redeploy.
  10. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.NETCore.App.Runtime.linux-arm64 to 10.0.13 or later, commit the lockfile and redeploy.
  11. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to 10.0.13 or later, commit the lockfile and redeploy.
  12. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm64 to 10.0.13 or later, commit the lockfile and redeploy.
  13. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.NETCore.App.Runtime.linux-musl-x64 to 10.0.13 or later, commit the lockfile and redeploy.
  14. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.NETCore.App.Runtime.linux-x64 to 10.0.13 or later, commit the lockfile and redeploy.
  15. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.NETCore.App.Runtime.osx-arm64 to 10.0.13 or later, commit the lockfile and redeploy.
  16. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.NETCore.App.Runtime.osx-x64 to 10.0.13 or later, commit the lockfile and redeploy.
  17. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.NETCore.App.Runtime.linux-arm to 9.0.21 or later, commit the lockfile and redeploy.
  18. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.NETCore.App.Runtime.linux-arm64 to 9.0.21 or later, commit the lockfile and redeploy.
  19. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to 9.0.21 or later, commit the lockfile and redeploy.
  20. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm64 to 9.0.21 or later, commit the lockfile and redeploy.
  21. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.NETCore.App.Runtime.linux-musl-x64 to 9.0.21 or later, commit the lockfile and redeploy.
  22. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.NETCore.App.Runtime.linux-x64 to 9.0.21 or later, commit the lockfile and redeploy.
  23. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.NETCore.App.Runtime.osx-arm64 to 9.0.21 or later, commit the lockfile and redeploy.
  24. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.NETCore.App.Runtime.osx-x64 to 9.0.21 or later, commit the lockfile and redeploy.
  25. On >= 11.0.0-preview.1, <= 11.0.0-rc.1: Upgrade Microsoft.NETCore.App.Runtime.linux-arm to 11.0.0-rc.2 or later, commit the lockfile and redeploy.
  26. On >= 11.0.0-preview.1, <= 11.0.0-rc.1: Upgrade Microsoft.NETCore.App.Runtime.linux-arm64 to 11.0.0-rc.2 or later, commit the lockfile and redeploy.
  27. On >= 11.0.0-preview.1, <= 11.0.0-rc.1: Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm to 11.0.0-rc.2 or later, commit the lockfile and redeploy.
  28. On >= 11.0.0-preview.1, <= 11.0.0-rc.1: Upgrade Microsoft.NETCore.App.Runtime.linux-musl-arm64 to 11.0.0-rc.2 or later, commit the lockfile and redeploy.
  29. On >= 11.0.0-preview.1, <= 11.0.0-rc.1: Upgrade Microsoft.NETCore.App.Runtime.linux-musl-x64 to 11.0.0-rc.2 or later, commit the lockfile and redeploy.
  30. On >= 11.0.0-preview.1, <= 11.0.0-rc.1: Upgrade Microsoft.NETCore.App.Runtime.linux-x64 to 11.0.0-rc.2 or later, commit the lockfile and redeploy.
  31. On >= 11.0.0-preview.1, <= 11.0.0-rc.1: Upgrade Microsoft.NETCore.App.Runtime.osx-arm64 to 11.0.0-rc.2 or later, commit the lockfile and redeploy.
  32. On >= 11.0.0-preview.1, <= 11.0.0-rc.1: Upgrade Microsoft.NETCore.App.Runtime.osx-x64 to 11.0.0-rc.2 or later, commit the lockfile and redeploy.
  33. If a vulnerable version was live, check your logs and rotate the secrets that server could read.

The advisory

## Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in Microsoft.NETCore.App.Runtime; System.Private.CoreLib. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. Unix named-mutex and shared-memory paths can be manipulated through insecure global directories, symlink races, and unsafe permission changes, allowing local attackers to truncate or overwrite files, widen directory permissions, or elevate privileges. ## Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/479 ## CVSS Details - **Version:** 3.1 - **Severity:** High - **Score:** 7.8 - **Vector:** `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` - **Weakness:** CWE-59 (Improper Link Resolution Before File Access ('Link Following')) ## Affected Platforms - **Platforms:** Linux, macOS - **Architectures:** All ## <a name="affected-packages"></a>Affected Packages The vulnerability affects Microsoft .NET projects that use an affected package version listed below. Package name | Affected version | Patched version ------------ | ---------------- | --------------- [Microsoft.NETCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-x64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-x64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-x64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.NETCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.NETCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-arm64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-musl-x64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-x64) | >= 11.0.0-preview.1, <= 11.0.0-rc.1 | 11.0.0-rc.2 [Microsoft.NETCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.osx-arm64) | >= 11.0.0-preview.1, <= 1…

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References

Merged from GitHub Advisory Database, CVE List. Last updated 23 Oct 2026. All vulnerabilities · RSS · JSON

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