Time-of-check Time-of-use (TOCTOU) Race Condition in .NET and Microsoft.DotNet.HotReload.Watch.Aspire - CVE-2026-114155

Vulnerability identifier: #VU165839

CSH Severity: Medium

CVSS v4: 7.1 [CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-114155

CWE-ID: CWE-367

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to escalate privileges and execute code with another user's permissions, gaining access to that user's data and resources.

The vulnerability exists due to a time-of-check time-of-use race condition in .NET when a resource changes between being checked and being used. A local user can win a race condition during an operation requiring user interaction to execute code with another user's permissions.

.NET
Microsoft.DotNet.HotReload.Watch.Aspire
Ubuntu
dotnet-runtime-8.0 (Ubuntu package)
dotnet-hostfxr-8.0 (Ubuntu package)
aspnetcore-runtime-8.0 (Ubuntu package)
dotnet-host-8.0 (Ubuntu package)
dotnet-sdk-8.0 (Ubuntu package)
dotnet8 (Ubuntu package)
dotnet-hostfxr-10.0 (Ubuntu package)
dotnet-host-10.0 (Ubuntu package)
aspnetcore-runtime-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-runtime-11.0 (Ubuntu package)
dotnet-host-11.0 (Ubuntu package)
dotnet-hostfxr-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 10.0.404, 11.0.100
Microsoft.DotNet.HotReload.Watch.Aspire - update to 11.0.100
dotnet-runtime-8.0 (Ubuntu package) - update to 8.0.34-0ubuntu1~24.04.1
dotnet-hostfxr-8.0 (Ubuntu package) - update to 8.0.34-0ubuntu1~24.04.1
aspnetcore-runtime-8.0 (Ubuntu package) - update to 8.0.34-0ubuntu1~24.04.1
dotnet-host-8.0 (Ubuntu package) - update to 8.0.34-0ubuntu1~24.04.1
dotnet-sdk-8.0 (Ubuntu package) - update to 8.0.134-0ubuntu1~24.04.1
dotnet8 (Ubuntu package) - update to 8.0.134-8.0.34-0ubuntu1~24.04.1
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-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
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-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-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-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-2026-114155
• 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