Ubuntu Security Notices
USN-8958-1

USN-8958-1: .NET vulnerabilities

Publication date

29 October 2026

Overview

Several security issues were fixed in .NET

Releases

26.10 26.04 LTS 24.04 LTS 22.04 LTS

Packages

dotnet10 - .NET CLI tools and runtime
dotnet11 - .NET CLI tools and runtime
dotnet8 - .NET CLI tools and runtime

Details

It was discovered that the .NET Blazor WebAssembly debug proxy did not
properly escape certain values. An attacker could possibly use this issue
to execute arbitrary code. The fix for this CVE was originally released via
USN-8942-1, but it was found to be incomplete. This issue only affected
dotnet10 and dotnet11. (CVE-2026-102870)

It was discovered that the Brotli decompression library used by .NET
incorrectly handled certain compressed streams. A remote attacker could
possibly use this issue to cause a denial of service or execute arbitrary
code. (CVE-2026-111497)

Alen Cheung discovered that .NET did not properly handle file ownership in
certain circumstances. An attacker could possibly use this issue to elevate
local privileges. (CVE-2026-114148)

Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release	Package Version
26.10 stonking	aspnetcore-runtime-10.0 – 10.0.14-0ubuntu1~26.10.1
	aspnetcore-runtime-11.0 – 11.0.0~rc3-0ubuntu1~26.10.1
	dotnet-host-10.0 – 10.0.14-0ubuntu1~26.10.1
	dotnet-host-11.0 – 11.0.0~rc3-0ubuntu1~26.10.1
	dotnet-hostfxr-10.0 – 10.0.14-0ubuntu1~26.10.1
	dotnet-hostfxr-11.0 – 11.0.0~rc3-0ubuntu1~26.10.1
	dotnet-runtime-10.0 – 10.0.14-0ubuntu1~26.10.1
	dotnet-runtime-11.0 – 11.0.0~rc3-0ubuntu1~26.10.1
	dotnet-sdk-10.0 – 10.0.114-0ubuntu1~26.10.1
	dotnet-sdk-11.0 – 11.0.100~rc3-0ubuntu1~26.10.1
	dotnet-sdk-aot-10.0 – 10.0.114-0ubuntu1~26.10.1
	dotnet-sdk-aot-11.0 – 11.0.100~rc3-0ubuntu1~26.10.1
	dotnet-sdk-dbg-10.0 – 10.0.114-0ubuntu1~26.10.1
	dotnet-sdk-dbg-11.0 – 11.0.100~rc3-0ubuntu1~26.10.1
	dotnet10 – 10.0.114-10.0.14-0ubuntu1~26.10.1
	dotnet11 – 11.0.100-11.0.0~rc3-0ubuntu1~26.10.1
26.04 LTS resolute	aspnetcore-runtime-10.0 – 10.0.14-0ubuntu1~26.04.1
	dotnet-host-10.0 – 10.0.14-0ubuntu1~26.04.1
	dotnet-hostfxr-10.0 – 10.0.14-0ubuntu1~26.04.1
	dotnet-runtime-10.0 – 10.0.14-0ubuntu1~26.04.1
	dotnet-sdk-10.0 – 10.0.114-0ubuntu1~26.04.1
	dotnet-sdk-aot-10.0 – 10.0.114-0ubuntu1~26.04.1
	dotnet-sdk-dbg-10.0 – 10.0.114-0ubuntu1~26.04.1
	dotnet10 – 10.0.114-10.0.14-0ubuntu1~26.04.1
24.04 LTS noble	aspnetcore-runtime-10.0 – 10.0.14-0ubuntu1~24.04.1
	aspnetcore-runtime-8.0 – 8.0.33-0ubuntu1~24.04.1
	dotnet-host-10.0 – 10.0.14-0ubuntu1~24.04.1
	dotnet-host-8.0 – 8.0.33-0ubuntu1~24.04.1
	dotnet-hostfxr-10.0 – 10.0.14-0ubuntu1~24.04.1
	dotnet-hostfxr-8.0 – 8.0.33-0ubuntu1~24.04.1
	dotnet-runtime-10.0 – 10.0.14-0ubuntu1~24.04.1
	dotnet-runtime-8.0 – 8.0.33-0ubuntu1~24.04.1
	dotnet-sdk-10.0 – 10.0.114-0ubuntu1~24.04.1
	dotnet-sdk-8.0 – 8.0.133-0ubuntu1~24.04.1
	dotnet-sdk-aot-10.0 – 10.0.114-0ubuntu1~24.04.1
	dotnet-sdk-dbg-10.0 – 10.0.114-0ubuntu1~24.04.1
	dotnet10 – 10.0.114-10.0.14-0ubuntu1~24.04.1
	dotnet8 – 8.0.133-8.0.33-0ubuntu1~24.04.1
22.04 LTS jammy	aspnetcore-runtime-8.0 – 8.0.33-0ubuntu1~22.04.1
	dotnet-host-8.0 – 8.0.33-0ubuntu1~22.04.1
	dotnet-hostfxr-8.0 – 8.0.33-0ubuntu1~22.04.1
	dotnet-runtime-8.0 – 8.0.33-0ubuntu1~22.04.1
	dotnet-sdk-8.0 – 8.0.133-0ubuntu1~22.04.1
	dotnet8 – 8.0.133-8.0.33-0ubuntu1~22.04.1

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USN-8958-1: .NET vulnerabilities

Packages

Details

Update instructions

Reduce your security exposure

References

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