{"id":"CVE-2021-26423","aliases":["BIT-dotnet-2021-26423","BIT-dotnet-sdk-2021-26423","GHSA-rh58-r7jh-xhx3"],"url":"https://o3.security/vulnerability/CVE-2021-26423","summary":".NET Core Elevation of Privilege Vulnerability","details":".NET Core and Visual Studio Denial of Service Vulnerability","published":"2021-08-12T18:15:08.537Z","modified":"2026-09-14T03:45:17.522203971Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.03902,"percentile":0.89739,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.win-x86","fixedVersion":"3.1.18"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.win-x86","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.win-x64","fixedVersion":"3.1.18"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.win-x64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.win-arm64","fixedVersion":"3.1.18"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.win-arm64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.win-arm","fixedVersion":"3.1.18"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.win-arm","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.osx-x64","fixedVersion":"3.1.18"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.osx-x64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.Mono.osx-x64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.Mono.LLVM.osx-x64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-x64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-arm64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.osx-x64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-x64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-arm64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.Mono.linux-x64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.Mono.linux-musl-x64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.Mono.linux-arm64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.Mono.linux-arm","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.linux-x64","fixedVersion":"3.1.18"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.linux-x64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.linux-musl-x64","fixedVersion":"3.1.18"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.linux-musl-x64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.linux-musl-arm64","fixedVersion":"3.1.18"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.linux-musl-arm64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.linux-musl-arm","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.rhel.6-x64","fixedVersion":"3.1.18"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.linux-arm64","fixedVersion":"3.1.18"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.linux-arm64","fixedVersion":"5.0.9"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.linux-arm","fixedVersion":"3.1.18"},{"ecosystem":"NuGet","name":"Microsoft.NETCore.App.Runtime.linux-arm","fixedVersion":"5.0.9"}],"fix":null,"references":[{"type":"WEB","url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26423"},{"type":"FIX","url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26423"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-14T03:45:17.522203971Z"}}