USN-8176-1: .NET vulnerabilities

Publication date

15 April 2026

Overview

Several security issues were fixed in .NET.


Packages

  • dotnet10 - .NET CLI tools and runtime
  • dotnet8 - .NET CLI tools and runtime
  • dotnet9 - .NET CLI tools and runtime

Details

Ludvig Pedersen discovered that the System.Security.Cryptography.Xml
library in .NET incorrectly handled certain XML inputs. An attacker could
possibly use this issue to consume excessive resources, resulting in a
denial of service. (CVE-2026-33116, CVE-2026-26171)

Ludvig Pedersen and Kevin Jones discovered that the
System.Security.Cryptography.Xml library in .NET incorrectly handled
certain XML inputs. An attacker could possibly use this issue to cause
.NET to crash, resulting in a denial of service. (CVE-2026-32203)

Ludvig Pedersen discovered that the System.Net.Mail component in .NET
incorrectly handled certain inputs. An attacker could possibly use this
issue to perform a network spoofing attack. (CVE-2026-32178)

Ludvig Pedersen discovered that the System.Security.Cryptography.Xml
library in .NET incorrectly handled certain XML inputs. An attacker could
possibly use this issue to consume excessive resources, resulting in a
denial of service. (CVE-2026-33116, CVE-2026-26171)

Ludvig Pedersen and Kevin Jones discovered that the
System.Security.Cryptography.Xml library in .NET incorrectly handled
certain XML inputs. An attacker could possibly use this issue to cause
.NET to crash, resulting in a denial of service. (CVE-2026-32203)

Ludvig Pedersen discovered that the System.Net.Mail component in .NET
incorrectly handled certain inputs. An attacker could possibly use this
issue to perform a network spoofing attack. (CVE-2026-32178)

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
25.10 questing aspnetcore-runtime-10.0 –  10.0.6-0ubuntu1~25.10.1
aspnetcore-runtime-8.0 –  8.0.26-0ubuntu1~25.10.1
aspnetcore-runtime-9.0 –  9.0.15-0ubuntu1~25.10.1
dotnet-host-10.0 –  10.0.6-0ubuntu1~25.10.1
dotnet-host-8.0 –  8.0.26-0ubuntu1~25.10.1
dotnet-host-9.0 –  9.0.15-0ubuntu1~25.10.1
dotnet-hostfxr-10.0 –  10.0.6-0ubuntu1~25.10.1
dotnet-hostfxr-8.0 –  8.0.26-0ubuntu1~25.10.1
dotnet-hostfxr-9.0 –  9.0.15-0ubuntu1~25.10.1
dotnet-runtime-10.0 –  10.0.6-0ubuntu1~25.10.1
dotnet-runtime-8.0 –  8.0.26-0ubuntu1~25.10.1
dotnet-runtime-9.0 –  9.0.15-0ubuntu1~25.10.1
dotnet-sdk-10.0 –  10.0.106-0ubuntu1~25.10.1
dotnet-sdk-8.0 –  8.0.126-0ubuntu1~25.10.1
dotnet-sdk-9.0 –  9.0.116-0ubuntu1~25.10.1
dotnet-sdk-aot-10.0 –  10.0.106-0ubuntu1~25.10.1
dotnet-sdk-aot-9.0 –  9.0.116-0ubuntu1~25.10.1
dotnet10 –  10.0.106-10.0.6-0ubuntu1~25.10.1
dotnet8 –  8.0.126-8.0.26-0ubuntu1~25.10.1
dotnet9 –  9.0.116-9.0.15-0ubuntu1~25.10.1
24.04 LTS noble aspnetcore-runtime-10.0 –  10.0.6-0ubuntu1~24.04.1
aspnetcore-runtime-8.0 –  8.0.26-0ubuntu1~24.04.1
dotnet-host-10.0 –  10.0.6-0ubuntu1~24.04.1
dotnet-host-8.0 –  8.0.26-0ubuntu1~24.04.1
dotnet-hostfxr-10.0 –  10.0.6-0ubuntu1~24.04.1
dotnet-hostfxr-8.0 –  8.0.26-0ubuntu1~24.04.1
dotnet-runtime-10.0 –  10.0.6-0ubuntu1~24.04.1
dotnet-runtime-8.0 –  8.0.26-0ubuntu1~24.04.1
dotnet-sdk-10.0 –  10.0.106-0ubuntu1~24.04.1
dotnet-sdk-8.0 –  8.0.126-0ubuntu1~24.04.1
dotnet-sdk-aot-10.0 –  10.0.106-0ubuntu1~24.04.1
dotnet10 –  10.0.106-10.0.6-0ubuntu1~24.04.1
dotnet8 –  8.0.126-8.0.26-0ubuntu1~24.04.1
22.04 LTS jammy aspnetcore-runtime-8.0 –  8.0.26-0ubuntu1~22.04.1
dotnet-host-8.0 –  8.0.26-0ubuntu1~22.04.1
dotnet-hostfxr-8.0 –  8.0.26-0ubuntu1~22.04.1
dotnet-runtime-8.0 –  8.0.26-0ubuntu1~22.04.1
dotnet-sdk-8.0 –  8.0.126-0ubuntu1~22.04.1
dotnet8 –  8.0.126-8.0.26-0ubuntu1~22.04.1

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