Stack-based buffer overflow in .NET - CVE-2026-109475

Vulnerability identifier: #VU165834

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-109475

CWE-ID: CWE-121

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a stack-based buffer overflow in .NET when processing network-supplied input. A remote attacker can send specially crafted input over a network to cause a denial of service.

.NET
Ubuntu
aspnetcore-runtime-8.0 (Ubuntu package)
dotnet-hostfxr-8.0 (Ubuntu package)
dotnet-runtime-8.0 (Ubuntu package)
dotnet-host-8.0 (Ubuntu package)
dotnet-sdk-8.0 (Ubuntu package)
dotnet8 (Ubuntu package)
aspnetcore-runtime-10.0 (Ubuntu package)
dotnet-host-10.0 (Ubuntu package)
dotnet-hostfxr-10.0 (Ubuntu package)
dotnet-runtime-10.0 (Ubuntu package)
dotnet-sdk-10.0 (Ubuntu package)
dotnet-sdk-aot-10.0 (Ubuntu package)
dotnet10 (Ubuntu package)
aspnetcore-runtime-11.0 (Ubuntu package)
dotnet-host-11.0 (Ubuntu package)
dotnet-hostfxr-11.0 (Ubuntu package)
dotnet-runtime-11.0 (Ubuntu package)
dotnet-sdk-11.0 (Ubuntu package)
dotnet-sdk-aot-11.0 (Ubuntu package)
dotnet11 (Ubuntu package)

Install security update from vendor's website.

.NET - addressed in versions 8.0.34, 9.0.23, 10.0.15, 11.0.0
aspnetcore-runtime-8.0 (Ubuntu package) - addressed in versions 8.0.34-0ubuntu1~22.04.1, 8.0.34-0ubuntu1~24.04.1
dotnet-hostfxr-8.0 (Ubuntu package) - addressed in versions 8.0.34-0ubuntu1~22.04.1, 8.0.34-0ubuntu1~24.04.1
dotnet-runtime-8.0 (Ubuntu package) - addressed in versions 8.0.34-0ubuntu1~22.04.1, 8.0.34-0ubuntu1~24.04.1
dotnet-host-8.0 (Ubuntu package) - addressed in versions 8.0.34-0ubuntu1~22.04.1, 8.0.34-0ubuntu1~24.04.1
dotnet-sdk-8.0 (Ubuntu package) - addressed in versions 8.0.134-0ubuntu1~22.04.1, 8.0.134-0ubuntu1~24.04.1
dotnet8 (Ubuntu package) - addressed in versions 8.0.134-8.0.34-0ubuntu1~22.04.1, 8.0.134-8.0.34-0ubuntu1~24.04.1
aspnetcore-runtime-10.0 (Ubuntu package) - addressed in versions 10.0.15-0ubuntu1~24.04.1, 10.0.15-0ubuntu1~26.04.1, 10.0.15-0ubuntu1~26.10.1
dotnet-host-10.0 (Ubuntu package) - addressed in versions 10.0.15-0ubuntu1~24.04.1, 10.0.15-0ubuntu1~26.04.1, 10.0.15-0ubuntu1~26.10.1
dotnet-hostfxr-10.0 (Ubuntu package) - addressed in versions 10.0.15-0ubuntu1~24.04.1, 10.0.15-0ubuntu1~26.04.1, 10.0.15-0ubuntu1~26.10.1
dotnet-runtime-10.0 (Ubuntu package) - addressed in versions 10.0.15-0ubuntu1~24.04.1, 10.0.15-0ubuntu1~26.04.1, 10.0.15-0ubuntu1~26.10.1
dotnet-sdk-10.0 (Ubuntu package) - addressed in versions 10.0.115-0ubuntu1~24.04.1, 10.0.115-0ubuntu1~26.04.1, 10.0.115-0ubuntu1~26.10.1
dotnet-sdk-aot-10.0 (Ubuntu package) - addressed in versions 10.0.115-0ubuntu1~24.04.1, 10.0.115-0ubuntu1~26.04.1, 10.0.115-0ubuntu1~26.10.1
dotnet10 (Ubuntu package) - addressed in versions 10.0.115-10.0.15-0ubuntu1~24.04.1, 10.0.115-10.0.15-0ubuntu1~26.04.1, 10.0.115-10.0.15-0ubuntu1~26.10.1
aspnetcore-runtime-11.0 (Ubuntu package) - update to 11.0.0-0ubuntu1~26.10.1
dotnet-host-11.0 (Ubuntu package) - update to 11.0.0-0ubuntu1~26.10.1
dotnet-hostfxr-11.0 (Ubuntu package) - update to 11.0.0-0ubuntu1~26.10.1
dotnet-runtime-11.0 (Ubuntu package) - update to 11.0.0-0ubuntu1~26.10.1
dotnet-sdk-11.0 (Ubuntu package) - update to 11.0.100-0ubuntu1~26.10.1
dotnet-sdk-aot-11.0 (Ubuntu package) - update to 11.0.100-0ubuntu1~26.10.1
dotnet11 (Ubuntu package) - update to 11.0.100-11.0.0-0ubuntu1~26.10.1

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-109475
• https://github.com/dotnet/core/blob/main/release-notes/11.0/11.0.0/11.0.0.md

• Multiple vulnerabilities in .NET
• Ubuntu update for dotnet10, dotnet11, dotnet8