CVE-2026-45591 ASP.NET Core Denial of Service Vulnerability
High 7.5
Published
Updated
Check this codebase for CVE-2026-45591 and fix it if it is affected.
What it is: CVE-2026-45591 is a high-severity denial of service vulnerability in Microsoft .Net, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-45591 in the wild and no public exploit code.
Affected packages and fixed versions:
- Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet): affected from 10.0.0; fixed in 10.0.9
- Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet): affected from 10.0.0; fixed in 10.0.9
- Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet): affected from 8.0.0; fixed in 8.0.28
- Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet): affected from 8.0.0; fixed in 8.0.28
- Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet): affected from 9.0.0; fixed in 9.0.17
- Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet): affected from 9.0.0; fixed in 9.0.17
- aspnet-core (Bitnami): affected from 8.0.0; fixed in 8.0.28, 9.0.17, 10.0.9
- dotnet (Bitnami): affected from 8.0.0; fixed in 8.0.28, 9.0.17, 10.0.9
- dotnet-sdk (Bitnami): affected from 8.0.0; fixed in 8.0.28, 9.0.17, 10.0.9
- Microsoft.AspNetCore.App.Runtime.osx-arm64 (NuGet): affected from 10.0.0; fixed in 10.0.9
- Microsoft.AspNetCore.App.Runtime.osx-arm64 (NuGet): affected from 10.0.0; fixed in 10.0.9
- Microsoft.AspNetCore.App.Runtime.osx-arm64 (NuGet): affected from 8.0.0; fixed in 8.0.28
Task:
1. 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.
2. 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.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.
Reference: https://insights.sbomify.com/CVE-2026-45591/ (Markdown: https://insights.sbomify.com/CVE-2026-45591/index.md)
An unauthorized attacker can cause a denial of service in ASP.NET Core through uncontrolled resource consumption.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-45591?
CVE-2026-45591 is a high-severity denial of service vulnerability in Microsoft .Net, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Uncontrolled resource consumption in ASP.NET Core allows an unauthorized attacker to deny service over a network.
Which versions are affected by CVE-2026-45591?
27 open source packages ship an affected version, including Microsoft.AspNetCore.App.Runtime.linux-x64, aspnet-core and dotnet. It affects 3 products.
| Package | Affected | Fixed in |
|---|---|---|
Microsoft.AspNetCore.App.Runtime.linux-x64 NuGet | From 10.0.0 | 10.0.9 |
Microsoft.AspNetCore.App.Runtime.linux-x64 NuGet | From 10.0.0 | 10.0.9 |
Microsoft.AspNetCore.App.Runtime.linux-x64 NuGet | From 8.0.0 | 8.0.28 |
Microsoft.AspNetCore.App.Runtime.linux-x64 NuGet | From 8.0.0 | 8.0.28 |
Microsoft.AspNetCore.App.Runtime.linux-x64 NuGet | From 9.0.0 | 9.0.17 |
Microsoft.AspNetCore.App.Runtime.linux-x64 NuGet | From 9.0.0 | 9.0.17 |
21 more packages
aspnet-core Bitnami | From 8.0.0 | 8.0.28, 9.0.17, 10.0.9 |
dotnet Bitnami | From 8.0.0 | 8.0.28, 9.0.17, 10.0.9 |
dotnet-sdk Bitnami | From 8.0.0 | 8.0.28, 9.0.17, 10.0.9 |
Microsoft.AspNetCore.App.Runtime.osx-arm64 NuGet | From 10.0.0 | 10.0.9 |
Microsoft.AspNetCore.App.Runtime.osx-arm64 NuGet | From 10.0.0 | 10.0.9 |
Microsoft.AspNetCore.App.Runtime.osx-arm64 NuGet | From 8.0.0 | 8.0.28 |
Microsoft.AspNetCore.App.Runtime.osx-arm64 NuGet | From 8.0.0 | 8.0.28 |
Microsoft.AspNetCore.App.Runtime.osx-arm64 NuGet | From 9.0.0 | 9.0.17 |
Microsoft.AspNetCore.App.Runtime.osx-arm64 NuGet | From 9.0.0 | 9.0.17 |
Microsoft.AspNetCore.App.Runtime.win-x64 NuGet | From 10.0.0 | 10.0.9 |
Microsoft.AspNetCore.App.Runtime.win-x64 NuGet | From 10.0.0 | 10.0.9 |
Microsoft.AspNetCore.App.Runtime.win-x64 NuGet | From 8.0.0 | 8.0.28 |
Microsoft.AspNetCore.App.Runtime.win-x64 NuGet | From 8.0.0 | 8.0.28 |
Microsoft.AspNetCore.App.Runtime.win-x64 NuGet | From 9.0.0 | 9.0.17 |
Microsoft.AspNetCore.App.Runtime.win-x64 NuGet | From 9.0.0 | 9.0.17 |
Microsoft.AspNetCore.SignalR.Protocols.MessagePack NuGet | From 10.0.0 | 10.0.9 |
Microsoft.AspNetCore.SignalR.Protocols.MessagePack NuGet | From 10.0.0 | 10.0.9 |
Microsoft.AspNetCore.SignalR.Protocols.MessagePack NuGet | From 8.0.0 | 8.0.28 |
Microsoft.AspNetCore.SignalR.Protocols.MessagePack NuGet | From 8.0.0 | 8.0.28 |
Microsoft.AspNetCore.SignalR.Protocols.MessagePack NuGet | From 9.0.0 | 9.0.17 |
Microsoft.AspNetCore.SignalR.Protocols.MessagePack NuGet | From 9.0.0 | 9.0.17 |
Products include Microsoft .Net, Microsoft Asp.net Core, Microsoft Visual Studio 2026.
How do I fix CVE-2026-45591?
Upgrade Microsoft.AspNetCore.App.Runtime.linux-x64 to a fixed version for your release line: 10.0.9, 8.0.28 or 9.0.17.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-45591 being exploited?
There is no known exploitation of CVE-2026-45591 in the wild and no public exploit code.
Other vulnerabilities in Microsoft .Net
- CVE-2024-43498 .NET and Visual Studio Remote Code Execution Vulnerability
- CVE-2024-0057 NET, .NET Framework, and Visual Studio Security Feature Bypass Vulnerability
- CVE-2026-96957 .NET Security Feature Bypass Vulnerability
- CVE-2026-69439 .NET and Visual Studio Elevation of Privilege Vulnerability
- CVE-2026-71328 .NET and Visual Studio Remote Code Execution Vulnerability
Sources
Also known as BIT-aspnet-core-2026-45591, BIT-dotnet-2026-45591, BIT-dotnet-sdk-2026-45591, GHSA-f8h2-vmm9-qhj6, MINI-gj7w-8cwc-qmfr, MINI-r89x-qfpj-vwqw and 1 more.