{"answers":{"affected":"40 open source packages ship an affected version, including Microsoft.NETCore.App.Runtime.linux-arm, dotnet and dotnet-sdk. It affects 5 products.","exploited":"There is no known exploitation of CVE-2021-26423 in the wild and no public exploit code.","fix":"Upgrade Microsoft.NETCore.App.Runtime.linux-arm to a fixed version for your release line: 3.1.18 or 5.0.9.","what":"CVE-2021-26423 is a high-severity denial of service vulnerability in Microsoft .Net, published on 12 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-26423 and fix it if it is affected.\n\nWhat it is: CVE-2021-26423 is a high-severity denial of service vulnerability in Microsoft .Net, published on 12 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-26423 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- Microsoft.NETCore.App.Runtime.linux-arm (NuGet): affected from 3.1.0; fixed in 3.1.18\n- Microsoft.NETCore.App.Runtime.linux-arm (NuGet): affected from 3.1.0; fixed in 3.1.18\n- Microsoft.NETCore.App.Runtime.linux-arm (NuGet): affected from 5.0.0; fixed in 5.0.9\n- Microsoft.NETCore.App.Runtime.linux-arm (NuGet): affected from 5.0.0; fixed in 5.0.9\n- dotnet (Bitnami): affected from 5.0.0; fixed in 5.0.9\n- dotnet-sdk (Bitnami): affected from 5.0.0; fixed in 5.0.9\n- Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-arm64 (NuGet): affected from 5.0.0; fixed in 5.0.9\n- Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-arm64 (NuGet): affected from 5.0.0; fixed in 5.0.9\n- Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-x64 (NuGet): affected from 5.0.0; fixed in 5.0.9\n- Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-x64 (NuGet): affected from 5.0.0; fixed in 5.0.9\n- Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.osx-x64 (NuGet): affected from 5.0.0; fixed in 5.0.9\n- Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.osx-x64 (NuGet): affected from 5.0.0; fixed in 5.0.9\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2021-26423/ (Markdown: https://insights.sbomify.com/CVE-2021-26423/index.md)","id":"CVE-2021-26423","markdown":"https://insights.sbomify.com/CVE-2021-26423/index.md","name":"CVE-2021-26423","record":{"aliases":["BIT-dotnet-2021-26423","BIT-dotnet-sdk-2021-26423","GHSA-rh58-r7jh-xhx3"],"analysis":{"component_type":"library","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":".NET Core and Visual Studio","requires_auth":"none","summary":"Attackers can cause a denial of service in .NET Core and Visual Studio environments, requiring users to apply vendor patches.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"microsoft","cpe":[{"product":".net","vendor":"microsoft"},{"product":".net_core","vendor":"microsoft"},{"product":"powershell_core","vendor":"microsoft"},{"product":"visual_studio_2017","vendor":"microsoft"},{"product":"visual_studio_2019","vendor":"microsoft"}],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","version":"3.1"},"cwes":[],"description":".NET Core and Visual Studio Denial of Service Vulnerability","ecosystems":["Bitnami","NuGet"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":".NET Core and Visual Studio Denial of Service Vulnerability","id":"CVE-2021-26423","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Bitnami","product":"microsoft:.net","products":["microsoft:.net","microsoft:visual_studio_2017","microsoft:visual_studio_2019"],"type":"denial_of_service","year":"2021"},"n_packages":68,"n_references":1,"next":{"headline":"Windows TCP/IP Remote Code Execution Vulnerability","id":"CVE-2021-26424"},"packages":[{"ecosystem":"Bitnami","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"dotnet","purl":"pkg:bitnami/dotnet","source":"BIT-dotnet-2021-26423"},{"ecosystem":"Bitnami","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"dotnet-sdk","purl":"pkg:bitnami/dotnet-sdk","source":"BIT-dotnet-sdk-2021-26423"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-arm64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-arm64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-arm64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-x64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-x64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-x64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.osx-x64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.osx-x64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.osx-x64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-arm64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-arm64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-arm64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-x64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-x64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-x64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.LLVM.osx-x64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.LLVM.osx-x64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.Mono.LLVM.osx-x64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.linux-arm","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.linux-arm","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.Mono.linux-arm","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.linux-arm64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.linux-arm64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.Mono.linux-arm64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.linux-musl-x64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.linux-musl-x64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.Mono.linux-musl-x64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.linux-x64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.linux-x64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.Mono.linux-x64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.osx-x64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.Mono.osx-x64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.Mono.osx-x64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["3.1.18"],"introduced":["3.1.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-arm","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["3.1.18"],"introduced":["3.1.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-arm","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.linux-arm","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-arm","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-arm","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.linux-arm","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["3.1.18"],"introduced":["3.1.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-arm64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["3.1.18"],"introduced":["3.1.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-arm64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.linux-arm64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-arm64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-arm64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.linux-arm64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-musl-arm","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-musl-arm","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["3.1.18"],"introduced":["3.1.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-musl-arm64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["3.1.18"],"introduced":["3.1.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-musl-arm64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-musl-arm64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["5.0.9"],"introduced":["5.0.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-musl-arm64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.linux-musl-arm64","source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["3.1.18"],"introduced":["3.1.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-musl-x64","purl":null,"source":"GHSA-rh58-r7jh-xhx3"},{"ecosystem":"NuGet","fixed":["3.1.18"],"introduced":["3.1.0"],"last_affected":[],"package":"Microsoft.NETCore.App.Runtime.linux-musl-x64","purl":"pkg:nuget/Microsoft.NETCore.App.Runtime.linux-musl-x64","source":"GHSA-rh58-r7jh-xhx3"}],"prev":{"headline":"Skype for Business and Lync Remote Code Execution Vulnerability","id":"CVE-2021-26422"},"products":[".NET 5.0",".NET Core 2.1",".NET Core 3.1","Microsoft Visual Studio 2017 version 15.9 (includes 15.0 - 15.8)","Microsoft Visual Studio 2019 version 16.10 (includes 16.0 - 16.9)","Microsoft Visual Studio 2019 version 16.4 (includes 16.0 - 16.3)","Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6)","Microsoft Visual Studio 2019 version 16.9 (includes 16.0 - 16.8)","PowerShell Core 7.0","PowerShell Core 7.1","Visual Studio 2019 for Mac version 8.10"],"published":"2021-08-12","related":[{"cvss_score":9.8,"headline":".NET and Visual Studio Remote Code Execution Vulnerability","id":"CVE-2024-43498","kev_date_added":null,"published":"2024-11-12"},{"cvss_score":9.1,"headline":"NET, .NET Framework, and Visual Studio Security Feature Bypass Vulnerability","id":"CVE-2024-0057","kev_date_added":null,"published":"2024-01-09"},{"cvss_score":8.8,"headline":".NET Security Feature Bypass Vulnerability","id":"CVE-2026-96957","kev_date_added":null,"published":"2026-10-13"},{"cvss_score":8.8,"headline":".NET and Visual Studio Elevation of Privilege Vulnerability","id":"CVE-2026-69439","kev_date_added":null,"published":"2026-09-08"},{"cvss_score":8.8,"headline":".NET and Visual Studio Remote Code Execution Vulnerability","id":"CVE-2026-71328","kev_date_added":null,"published":"2026-09-08"},{"cvss_score":8.8,"headline":"ASP.NET Core Elevation of Privilege Vulnerability","id":"CVE-2026-47300","kev_date_added":null,"published":"2026-07-14"},{"cvss_score":8.8,"headline":"ASP.NET Core Elevation of Privilege Vulnerability","id":"CVE-2026-47303","kev_date_added":null,"published":"2026-07-14"}],"sources":[{"class":"attribution","licence":"Apache-2.0","name":"Bitnami","prefix":"BIT"},{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-08-10","vendors":["Microsoft"]},"summary":"Attackers can cause a denial of service in .NET Core and Visual Studio environments, requiring users to apply vendor patches.","url":"https://insights.sbomify.com/CVE-2021-26423/"}