high · 7.5 Patched

Microsoft Security Advisory CVE-2026-70181 - ASP.NET Core Denial of Service Vulnerability

CVE-2026-70181 · GHSA-w5qq-qrpp-rf4c · published 13 Oct 2026

How serious is it

  • Severity: high, CVSS score 7.5 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-2026-70181?

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.AspNetCore.App.Runtime.linux-arm (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.AspNetCore.App.Runtime.osx-arm64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.AspNetCore.App.Runtime.win-arm (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet) >= 9.0.0, <= 9.0.20
  • Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.AspNetCore.App.Runtime.osx-arm64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.AspNetCore.App.Runtime.win-arm (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet) >= 10.0.0, <= 10.0.12
  • Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.AspNetCore.App.Runtime.osx-arm64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.AspNetCore.App.Runtime.win-arm (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet) >= 8.0.0, <= 8.0.31
  • Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet) >= 8.0.0, <= 8.0.31

How to check

  1. Look for Microsoft.AspNetCore.App.Runtime.linux-arm in your lockfile and compare its version with the range above.
  2. Look for Microsoft.AspNetCore.App.Runtime.linux-arm64 in your lockfile and compare its version with the range above.
  3. Look for Microsoft.AspNetCore.App.Runtime.linux-musl-arm in your lockfile and compare its version with the range above.
  4. Look for Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 in your lockfile and compare its version with the range above.
  5. Look for Microsoft.AspNetCore.App.Runtime.linux-musl-x64 in your lockfile and compare its version with the range above.
  6. Look for Microsoft.AspNetCore.App.Runtime.linux-x64 in your lockfile and compare its version with the range above.
  7. Look for Microsoft.AspNetCore.App.Runtime.osx-arm64 in your lockfile and compare its version with the range above.
  8. Look for Microsoft.AspNetCore.App.Runtime.osx-x64 in your lockfile and compare its version with the range above.
  9. Look for Microsoft.AspNetCore.App.Runtime.win-arm in your lockfile and compare its version with the range above.
  10. Look for Microsoft.AspNetCore.App.Runtime.win-arm64 in your lockfile and compare its version with the range above.
  11. Look for Microsoft.AspNetCore.App.Runtime.win-x64 in your lockfile and compare its version with the range above.
  12. Look for Microsoft.AspNetCore.App.Runtime.win-x86 in your lockfile and compare its version with the range above.
  13. 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 >= 9.0.0, <= 9.0.20: Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm to 9.0.21 or later, commit the lockfile and redeploy.
  2. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm64 to 9.0.21 or later, commit the lockfile and redeploy.
  3. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm to 9.0.21 or later, commit the lockfile and redeploy.
  4. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 to 9.0.21 or later, commit the lockfile and redeploy.
  5. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-x64 to 9.0.21 or later, commit the lockfile and redeploy.
  6. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.AspNetCore.App.Runtime.linux-x64 to 9.0.21 or later, commit the lockfile and redeploy.
  7. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.AspNetCore.App.Runtime.osx-arm64 to 9.0.21 or later, commit the lockfile and redeploy.
  8. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.AspNetCore.App.Runtime.osx-x64 to 9.0.21 or later, commit the lockfile and redeploy.
  9. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.AspNetCore.App.Runtime.win-arm to 9.0.21 or later, commit the lockfile and redeploy.
  10. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.AspNetCore.App.Runtime.win-arm64 to 9.0.21 or later, commit the lockfile and redeploy.
  11. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.AspNetCore.App.Runtime.win-x64 to 9.0.21 or later, commit the lockfile and redeploy.
  12. On >= 9.0.0, <= 9.0.20: Upgrade Microsoft.AspNetCore.App.Runtime.win-x86 to 9.0.21 or later, commit the lockfile and redeploy.
  13. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm to 10.0.13 or later, commit the lockfile and redeploy.
  14. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm64 to 10.0.13 or later, commit the lockfile and redeploy.
  15. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm to 10.0.13 or later, commit the lockfile and redeploy.
  16. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 to 10.0.13 or later, commit the lockfile and redeploy.
  17. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-x64 to 10.0.13 or later, commit the lockfile and redeploy.
  18. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.AspNetCore.App.Runtime.linux-x64 to 10.0.13 or later, commit the lockfile and redeploy.
  19. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.AspNetCore.App.Runtime.osx-arm64 to 10.0.13 or later, commit the lockfile and redeploy.
  20. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.AspNetCore.App.Runtime.osx-x64 to 10.0.13 or later, commit the lockfile and redeploy.
  21. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.AspNetCore.App.Runtime.win-arm to 10.0.13 or later, commit the lockfile and redeploy.
  22. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.AspNetCore.App.Runtime.win-arm64 to 10.0.13 or later, commit the lockfile and redeploy.
  23. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.AspNetCore.App.Runtime.win-x64 to 10.0.13 or later, commit the lockfile and redeploy.
  24. On >= 10.0.0, <= 10.0.12: Upgrade Microsoft.AspNetCore.App.Runtime.win-x86 to 10.0.13 or later, commit the lockfile and redeploy.
  25. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm to 8.0.32 or later, commit the lockfile and redeploy.
  26. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm64 to 8.0.32 or later, commit the lockfile and redeploy.
  27. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm to 8.0.32 or later, commit the lockfile and redeploy.
  28. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 to 8.0.32 or later, commit the lockfile and redeploy.
  29. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-x64 to 8.0.32 or later, commit the lockfile and redeploy.
  30. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.AspNetCore.App.Runtime.linux-x64 to 8.0.32 or later, commit the lockfile and redeploy.
  31. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.AspNetCore.App.Runtime.osx-arm64 to 8.0.32 or later, commit the lockfile and redeploy.
  32. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.AspNetCore.App.Runtime.osx-x64 to 8.0.32 or later, commit the lockfile and redeploy.
  33. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.AspNetCore.App.Runtime.win-arm to 8.0.32 or later, commit the lockfile and redeploy.
  34. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.AspNetCore.App.Runtime.win-arm64 to 8.0.32 or later, commit the lockfile and redeploy.
  35. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.AspNetCore.App.Runtime.win-x64 to 8.0.32 or later, commit the lockfile and redeploy.
  36. On >= 8.0.0, <= 8.0.31: Upgrade Microsoft.AspNetCore.App.Runtime.win-x86 to 8.0.32 or later, commit the lockfile and redeploy.
  37. 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.AspNetCore.WebUtilities. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. FileBufferingReadStream eagerly rents buffers during multipart processing, allowing memory exhaustion and denial of service. ## Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/459 ## CVSS Details - **Version:** 3.1 - **Severity:** High - **Score:** 7.5 - **Vector:** `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H` - **Weakness:** CWE-770 (Allocation of Resources Without Limits or Throttling) ## Affected Platforms - **Platforms:** Windows, 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.AspNetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-arm) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.AspNetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.AspNetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-musl-arm) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.AspNetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-musl-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.AspNetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-musl-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.AspNetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.AspNetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.osx-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.AspNetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.osx-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.AspNetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.win-arm) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.AspNetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.win-arm64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.AspNetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.win-x64) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.AspNetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.win-x86) | >= 9.0.0, <= 9.0.20 | 9.0.21 [Microsoft.AspNetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-arm) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.AspNetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.AspNetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-musl-arm) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.AspNetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-musl-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.AspNetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-musl-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.AspNetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.AspNetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.osx-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.AspNetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.osx-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.AspNetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.win-arm) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.AspNetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.win-arm64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.AspNetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.win-x64) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.AspNetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.win-x86) | >= 10.0.0, <= 10.0.12 | 10.0.13 [Microsoft.AspNetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-arm) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.AspNetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.AspNetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-musl-arm) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.AspNetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-musl-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.AspNetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-musl-x64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.AspNetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.linux-x64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.AspNetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.osx-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.AspNetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.AspNetCore.App.Runtime.osx-x64) | >= 8.0.0, <…

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References

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

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