# Microsoft .NET Brotli decoder out-of-bounds write Source: https://junglewise.ai/threats/microsoft-security-advisory-net-brotli-decoder-out-of-bounds-write-b42e3b43 Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats Published: 2026-11-03. Updated: 2026-11-03 License: CC BY 4.0 with a link back Severity: high · CVSS 8.1 · Published 2026-11-03 A buffer overflow vulnerability in the Brotli decompression library used by .NET allows attackers to read or corrupt process memory when applications decompress attacker-controlled Brotli data. Applications are exposed only if they explicitly enable Brotli decompression in ASP.NET Core, HttpClient, or use Brotli decompression APIs directly; default configurations are not affected. Successful exploitation could lead to information disclosure, denial of service, or privilege escalation. Technologies: [Microsoft .Net](https://junglewise.ai/threats/technologies/microsoft-net), [Microsoft.NETCore.App.Runtime.browser-wasm (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-browser-wasm), [Microsoft.NetCore.App.Runtime.linux-arm (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-linux-arm), [Microsoft.NetCore.App.Runtime.linux-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-linux-arm64), [Microsoft.NetCore.App.Runtime.linux-musl-arm (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-linux-musl-arm), [Microsoft.NetCore.App.Runtime.linux-musl-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-linux-musl-arm64), [Microsoft.NetCore.App.Runtime.linux-musl-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-linux-musl-x64), [Microsoft.NetCore.App.Runtime.linux-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-linux-x64), [Microsoft.NETCore.App.Runtime.Mono.android-arm (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-android-arm), [Microsoft.NETCore.App.Runtime.Mono.android-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-android-arm64), [Microsoft.NETCore.App.Runtime.Mono.android-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-android-x64), [Microsoft.NETCore.App.Runtime.Mono.android-x86 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-android-x86), [Microsoft.NETCore.App.Runtime.Mono.browser-wasm (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-browser-wasm), [Microsoft.NETCore.App.Runtime.Mono.ios-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-ios-arm64), [Microsoft.NETCore.App.Runtime.Mono.iossimulator-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-iossimulator-arm64), [Microsoft.NETCore.App.Runtime.Mono.iossimulator-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-iossimulator-x64), [Microsoft.NETCore.App.Runtime.Mono.linux-arm (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-linux-arm), [Microsoft.NETCore.App.Runtime.Mono.linux-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-linux-arm64), [Microsoft.NETCore.App.Runtime.Mono.linux-musl-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-linux-musl-x64), [Microsoft.NETCore.App.Runtime.Mono.linux-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-linux-x64), [Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-llvm-linux-arm64), [Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-llvm-linux-x64), [Microsoft.NETCore.App.Runtime.Mono.LLVM.osx-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-llvm-osx-x64), [Microsoft.NETCore.App.Runtime.Mono.maccatalyst-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-maccatalyst-arm64), [Microsoft.NETCore.App.Runtime.Mono.maccatalyst-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-maccatalyst-x64), [Microsoft.NETCore.App.Runtime.Mono.osx-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-osx-arm64), [Microsoft.NETCore.App.Runtime.Mono.osx-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-osx-x64), [Microsoft.NETCore.App.Runtime.Mono.tvos-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-tvos-arm64), [Microsoft.NETCore.App.Runtime.Mono.tvossimulator-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-tvossimulator-arm64), [Microsoft.NETCore.App.Runtime.Mono.tvossimulator-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-tvossimulator-x64), [Microsoft.NETCore.App.Runtime.Mono.win-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-win-x64), [Microsoft.NETCore.App.Runtime.Mono.win-x86 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-mono-win-x86), [Microsoft.NetCore.App.Runtime.osx-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-osx-arm64), [Microsoft.NetCore.App.Runtime.osx-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-osx-x64), [Microsoft.NetCore.App.Runtime.win-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-win-arm64), [Microsoft.NetCore.App.Runtime.win-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-win-x64), [Microsoft.NetCore.App.Runtime.win-x86 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-netcore-app-runtime-win-x86). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft), [NuGet](https://junglewise.ai/threats/vendors/nuget). ## Quick answers **Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild. **How severe is This vulnerability?** High severity, with a CVSS score of 8.1, published 3 November 2026. **Which products and versions are affected?** Microsoft .Net 8.0.0 to 8.0.32, 9.0.0 to 9.0.21, 10.0.0 to 10.0.13, 11.0.0 previews before 11.0.0-rc.3.26522.148; Microsoft .NET ILCompiler 8.0.0 to 8.0.32, 9.0.0 to 9.0.21, 10.0.0 to 10.0.13, 11.0.0 previews before 11.0.0-rc.3.26522.148; Microsoft.DotNet.ILCompiler (NuGet) >= 8.0.0, < 8.0.33, ECOSYSTEM:introduced=8.0.0,fixed=8.0.33; Microsoft.NETCore.App.Runtime.android-arm (NuGet) >= 11.0.0-preview.1, < 11.0.0-rc.3.26522.148, ECOSYSTEM:introduced=11.0.0-preview.1,fixed=11.0.0-rc.3.26522.148; and 75 more. **Is there a fix for This vulnerability?** Yes. Microsoft.DotNet.ILCompiler (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.android-arm (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later; Microsoft.NETCore.App.Runtime.android-arm64 (NuGet): upgrade to 10.0.14 or later; Microsoft.NETCore.App.Runtime.android-x64 (NuGet): upgrade to 10.0.14 or later; Microsoft.NETCore.App.Runtime.browser-wasm (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later; Microsoft.NETCore.App.Runtime.ios-arm64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later; Microsoft.NETCore.App.Runtime.iossimulator-arm64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later; Microsoft.NETCore.App.Runtime.iossimulator-x64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later; Microsoft.NetCore.App.Runtime.linux-arm (NuGet): upgrade to 8.0.33 or later; Microsoft.NetCore.App.Runtime.linux-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.linux-bionic-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.linux-bionic-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NetCore.App.Runtime.linux-musl-arm (NuGet): upgrade to 8.0.33 or later; Microsoft.NetCore.App.Runtime.linux-musl-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NetCore.App.Runtime.linux-musl-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NetCore.App.Runtime.linux-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.maccatalyst-arm64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later; Microsoft.NETCore.App.Runtime.maccatalyst-x64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later; Microsoft.NETCore.App.Runtime.Mono.android-arm (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.android-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.android-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.android-x86 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.browser-wasm (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.ios-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.iossimulator-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.iossimulator-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.linux-arm (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.linux-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.linux-musl-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.linux-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.LLVM.osx-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.maccatalyst-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.maccatalyst-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.multithread.browser-wasm (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.osx-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.osx-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.tvos-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.tvossimulator-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.tvossimulator-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.wasi-wasm (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.win-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.Mono.win-x86 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.NativeAOT.android-arm (NuGet): upgrade to 10.0.14 or later; Microsoft.NETCore.App.Runtime.NativeAOT.android-arm64 (NuGet): upgrade to 10.0.14 or later; Microsoft.NETCore.App.Runtime.NativeAOT.android-x64 (NuGet): upgrade to 10.0.14 or later; Microsoft.NETCore.App.Runtime.NativeAOT.ios-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.NativeAOT.iossimulator-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.NativeAOT.iossimulator-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.NativeAOT.linux-arm (NuGet): upgrade to 9.0.22 or later; Microsoft.NETCore.App.Runtime.NativeAOT.linux-arm64 (NuGet): upgrade to 9.0.22 or later; Microsoft.NETCore.App.Runtime.NativeAOT.linux-bionic-arm (NuGet): upgrade to 9.0.22 or later; Microsoft.NETCore.App.Runtime.NativeAOT.linux-bionic-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.NativeAOT.linux-bionic-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.NativeAOT.linux-musl-arm (NuGet): upgrade to 9.0.22 or later; Microsoft.NETCore.App.Runtime.NativeAOT.linux-musl-arm64 (NuGet): upgrade to 9.0.22 or later; Microsoft.NETCore.App.Runtime.NativeAOT.linux-musl-x64 (NuGet): upgrade to 9.0.22 or later; Microsoft.NETCore.App.Runtime.NativeAOT.linux-x64 (NuGet): upgrade to 9.0.22 or later; Microsoft.NETCore.App.Runtime.NativeAOT.maccatalyst-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.NativeAOT.maccatalyst-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.NativeAOT.osx-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.NativeAOT.osx-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.NativeAOT.tvos-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.NativeAOT.tvossimulator-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.NativeAOT.tvossimulator-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.NativeAOT.win-arm64 (NuGet): upgrade to 9.0.22 or later; Microsoft.NETCore.App.Runtime.NativeAOT.win-x64 (NuGet): upgrade to 9.0.22 or later; Microsoft.NETCore.App.Runtime.NativeAOT.win-x86 (NuGet): upgrade to 9.0.22 or later; Microsoft.NetCore.App.Runtime.osx-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NetCore.App.Runtime.osx-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NETCore.App.Runtime.tvos-arm64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later; Microsoft.NETCore.App.Runtime.tvossimulator-arm64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later; Microsoft.NETCore.App.Runtime.tvossimulator-x64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later; Microsoft.NetCore.App.Runtime.win-arm64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NetCore.App.Runtime.win-x64 (NuGet): upgrade to 8.0.33 or later; Microsoft.NetCore.App.Runtime.win-x86 (NuGet): upgrade to 8.0.33 or later. Until then: Disable Brotli decompression if already enabled: remove the "br" entry from ASP.NET Core request decompression configuration, or update HttpClientHandler/SocketsHttpHandler to exclude DecompressionMethods.Brotli. Applications directly using Brotli decompression APIs must stop processing untrusted Brotli data until patched. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve. **How is This vulnerability attacked?** It is attacked over the network, in a software library. **Am I affected?** Check whether you run Microsoft .Net, Microsoft .NET ILCompiler, Microsoft.DotNet.ILCompiler (NuGet) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you. ## How to fix - Microsoft.DotNet.ILCompiler (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.DotNet.ILCompiler --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.android-arm (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.android-arm --version 11.0.0-rc.3.26522.148 ``` - Microsoft.NETCore.App.Runtime.android-arm64 (NuGet): upgrade to 10.0.14 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.android-arm64 --version 10.0.14 ``` - Microsoft.NETCore.App.Runtime.android-x64 (NuGet): upgrade to 10.0.14 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.android-x64 --version 10.0.14 ``` - Microsoft.NETCore.App.Runtime.browser-wasm (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.browser-wasm --version 11.0.0-rc.3.26522.148 ``` - Microsoft.NETCore.App.Runtime.ios-arm64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.ios-arm64 --version 11.0.0-rc.3.26522.148 ``` - Microsoft.NETCore.App.Runtime.iossimulator-arm64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.iossimulator-arm64 --version 11.0.0-rc.3.26522.148 ``` - Microsoft.NETCore.App.Runtime.iossimulator-x64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.iossimulator-x64 --version 11.0.0-rc.3.26522.148 ``` - Microsoft.NetCore.App.Runtime.linux-arm (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NetCore.App.Runtime.linux-arm --version 8.0.33 ``` - Microsoft.NetCore.App.Runtime.linux-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NetCore.App.Runtime.linux-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.linux-bionic-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.linux-bionic-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.linux-bionic-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.linux-bionic-x64 --version 8.0.33 ``` - Microsoft.NetCore.App.Runtime.linux-musl-arm (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NetCore.App.Runtime.linux-musl-arm --version 8.0.33 ``` - Microsoft.NetCore.App.Runtime.linux-musl-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NetCore.App.Runtime.linux-musl-arm64 --version 8.0.33 ``` - Microsoft.NetCore.App.Runtime.linux-musl-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NetCore.App.Runtime.linux-musl-x64 --version 8.0.33 ``` - Microsoft.NetCore.App.Runtime.linux-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NetCore.App.Runtime.linux-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.maccatalyst-arm64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.maccatalyst-arm64 --version 11.0.0-rc.3.26522.148 ``` - Microsoft.NETCore.App.Runtime.maccatalyst-x64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.maccatalyst-x64 --version 11.0.0-rc.3.26522.148 ``` - Microsoft.NETCore.App.Runtime.Mono.android-arm (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.android-arm --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.android-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.android-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.android-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.android-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.android-x86 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.android-x86 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.browser-wasm (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.browser-wasm --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.ios-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.ios-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.iossimulator-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.iossimulator-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.iossimulator-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.iossimulator-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.linux-arm (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.linux-arm --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.linux-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.linux-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.linux-musl-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.linux-musl-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.linux-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.linux-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.LLVM.osx-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.LLVM.osx-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.maccatalyst-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.maccatalyst-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.maccatalyst-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.maccatalyst-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.multithread.browser-wasm (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.multithread.browser-wasm --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.osx-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.osx-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.osx-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.osx-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.tvos-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.tvos-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.tvossimulator-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.tvossimulator-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.tvossimulator-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.tvossimulator-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.wasi-wasm (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.wasi-wasm --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.win-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.win-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.Mono.win-x86 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.Mono.win-x86 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.android-arm (NuGet): upgrade to 10.0.14 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.android-arm --version 10.0.14 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.android-arm64 (NuGet): upgrade to 10.0.14 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.android-arm64 --version 10.0.14 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.android-x64 (NuGet): upgrade to 10.0.14 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.android-x64 --version 10.0.14 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.ios-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.ios-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.iossimulator-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.iossimulator-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.iossimulator-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.iossimulator-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.linux-arm (NuGet): upgrade to 9.0.22 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.linux-arm --version 9.0.22 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.linux-arm64 (NuGet): upgrade to 9.0.22 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.linux-arm64 --version 9.0.22 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.linux-bionic-arm (NuGet): upgrade to 9.0.22 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.linux-bionic-arm --version 9.0.22 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.linux-bionic-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.linux-bionic-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.linux-bionic-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.linux-bionic-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.linux-musl-arm (NuGet): upgrade to 9.0.22 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.linux-musl-arm --version 9.0.22 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.linux-musl-arm64 (NuGet): upgrade to 9.0.22 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.linux-musl-arm64 --version 9.0.22 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.linux-musl-x64 (NuGet): upgrade to 9.0.22 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.linux-musl-x64 --version 9.0.22 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.linux-x64 (NuGet): upgrade to 9.0.22 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.linux-x64 --version 9.0.22 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.maccatalyst-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.maccatalyst-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.maccatalyst-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.maccatalyst-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.osx-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.osx-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.osx-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.osx-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.tvos-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.tvos-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.tvossimulator-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.tvossimulator-arm64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.tvossimulator-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.tvossimulator-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.win-arm64 (NuGet): upgrade to 9.0.22 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.win-arm64 --version 9.0.22 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.win-x64 (NuGet): upgrade to 9.0.22 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.win-x64 --version 9.0.22 ``` - Microsoft.NETCore.App.Runtime.NativeAOT.win-x86 (NuGet): upgrade to 9.0.22 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.NativeAOT.win-x86 --version 9.0.22 ``` - Microsoft.NetCore.App.Runtime.osx-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NetCore.App.Runtime.osx-arm64 --version 8.0.33 ``` - Microsoft.NetCore.App.Runtime.osx-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NetCore.App.Runtime.osx-x64 --version 8.0.33 ``` - Microsoft.NETCore.App.Runtime.tvos-arm64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.tvos-arm64 --version 11.0.0-rc.3.26522.148 ``` - Microsoft.NETCore.App.Runtime.tvossimulator-arm64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.tvossimulator-arm64 --version 11.0.0-rc.3.26522.148 ``` - Microsoft.NETCore.App.Runtime.tvossimulator-x64 (NuGet): upgrade to 11.0.0-rc.3.26522.148 or later ```sh dotnet add package Microsoft.NETCore.App.Runtime.tvossimulator-x64 --version 11.0.0-rc.3.26522.148 ``` - Microsoft.NetCore.App.Runtime.win-arm64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NetCore.App.Runtime.win-arm64 --version 8.0.33 ``` - Microsoft.NetCore.App.Runtime.win-x64 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NetCore.App.Runtime.win-x64 --version 8.0.33 ``` - Microsoft.NetCore.App.Runtime.win-x86 (NuGet): upgrade to 8.0.33 or later ```sh dotnet add package Microsoft.NetCore.App.Runtime.win-x86 --version 8.0.33 ``` Disable Brotli decompression if already enabled: remove the "br" entry from ASP.NET Core request decompression configuration, or update HttpClientHandler/SocketsHttpHandler to exclude DecompressionMethods.Brotli. Applications directly using Brotli decompression APIs must stop processing untrusted Brotli data until patched. ## Technical details An out-of-bounds write flaw exists in the Brotli decoder (CWE-787) bundled with .NET runtimes and NativeAOT packages. The vulnerability requires network-accessible attacker-controlled Brotli-compressed data and is triggered only when applications explicitly configure decompression (ASP.NET Core request decompression with Brotli support, HttpClient automatic decompression with Brotli enabled, or direct use of BrotliStream/BrotliDecoder APIs). Memory corruption enables information disclosure and potentially arbitrary code execution. ## Affected products - Microsoft .NET 8.0.0 to 8.0.32, 9.0.0 to 9.0.21, 10.0.0 to 10.0.13, 11.0.0 previews before 11.0.0-rc.3.26522.148 - Microsoft .NET ILCompiler 8.0.0 to 8.0.32, 9.0.0 to 9.0.21, 10.0.0 to 10.0.13, 11.0.0 previews before 11.0.0-rc.3.26522.148 ## Timeline - 2026-10-25: advisory: Microsoft Security Advisory published ## Related threats - [Microsoft Visual Studio heap buffer overflow RCE](https://junglewise.ai/threats/duplicate-advisory-microsoft-security-advisory-visual-studio-remote-224be73b) - [Microsoft Visual Studio heap-based buffer overflow](https://junglewise.ai/threats/duplicate-advisory-microsoft-security-advisory-visual-studio-remote-6a4b9d28) - [Microsoft Visual Studio deserialization remote code execution](https://junglewise.ai/threats/duplicate-advisory-microsoft-security-advisory-visual-studio-remote-1eb2f932) - [Microsoft Visual Studio heap-based buffer overflow](https://junglewise.ai/threats/duplicate-advisory-microsoft-security-advisory-visual-studio-remote-ba83a5c9) - [Microsoft Visual Studio stack-based buffer overflow](https://junglewise.ai/threats/duplicate-advisory-microsoft-security-advisory-visual-studio-remote-d956164d)