Home / mailings [USN-8176-1] .NET vulnerabilities
Posted on 16 April 2026
Ubuntu Security==========================================================================Ubuntu Security Notice USN-8176-1
April 15, 2026
dotnet8, dotnet9, dotnet10 vulnerabilities
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 25.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS
Summary:
Several security issues were fixed in .NET.
Software Description:
- 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)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 25.10
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
Ubuntu 24.04 LTS
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
Ubuntu 22.04 LTS
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
In general, a standard system update will make all the necessary changes.
References:
https://ubuntu.com/security/notices/USN-8176-1
CVE-2026-26171, CVE-2026-32178, CVE-2026-32203, CVE-2026-33116
Package Information:
https://launchpad.net/ubuntu/+source/dotnet10/10.0.106-10.0.6-0ubuntu1~25.10.1
https://launchpad.net/ubuntu/+source/dotnet8/8.0.126-8.0.26-0ubuntu1~25.10.1
https://launchpad.net/ubuntu/+source/dotnet9/9.0.116-9.0.15-0ubuntu1~25.10.1
https://launchpad.net/ubuntu/+source/dotnet10/10.0.106-10.0.6-0ubuntu1~24.04.1
https://launchpad.net/ubuntu/+source/dotnet8/8.0.126-8.0.26-0ubuntu1~24.04.1
https://launchpad.net/ubuntu/+source/dotnet8/8.0.126-8.0.26-0ubuntu1~22.04.1
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