Is CVE-2026-70183 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-70183 being exploited in the wild.

How severe is CVE-2026-70183?

High severity, with a CVSS score of 7.5, published 13 October 2026.

Which products and versions are affected?

Microsoft Asp.Net Core 8.0.0 through 8.0.31, 9.0.0 through 9.0.20, 10.0.0 through 10.0.12, 11.0.0-preview.1 through 11.0.0-rc.1; Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet) >= 8.0.0, = 8.0.0, = 8.0.0, <= 8.0.31, ECOSYSTEM:introduced=8.0.0,fixed=8.0.32; and 9 more.

How is CVE-2026-70183 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-70183?

Check whether you run Microsoft Asp.Net Core, Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet), Microsoft.AspNetCore.App.Runtime.linux-arm64 (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.

CVE-2026-70183: Microsoft ASP.NET Core authorization bypass in Blazor AuthorizeRouteView

Q: Is there a fix for CVE-2026-70183?

Yes. Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.osx-arm64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.win-arm (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet): upgrade to 8.0.32 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-70183 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-70183?

Check whether you run Microsoft Asp.Net Core, Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet), Microsoft.AspNetCore.App.Runtime.linux-arm64 (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.

CVE-2026-70183 · Severity: high · CVSS 7.5 · Published 2026-10-13

A race condition in Microsoft ASP.NET Core's Blazor authorization component can allow stale authorization decisions to be reapplied after page navigation or authorization-state changes. An authenticated attacker could exploit this to bypass authorization checks and access protected resources they should not have permission to view or modify.

Quick answers

Is CVE-2026-70183 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-70183 being exploited in the wild.
How severe is CVE-2026-70183?: High severity, with a CVSS score of 7.5, published 13 October 2026.
Which products and versions are affected?: Microsoft Asp.Net Core 8.0.0 through 8.0.31, 9.0.0 through 9.0.20, 10.0.0 through 10.0.12, 11.0.0-preview.1 through 11.0.0-rc.1; Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet) >= 8.0.0, <= 8.0.31, ECOSYSTEM:introduced=8.0.0,fixed=8.0.32; Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet) >= 8.0.0, <= 8.0.31, ECOSYSTEM:introduced=8.0.0,fixed=8.0.32; Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet) >= 8.0.0, <= 8.0.31, ECOSYSTEM:introduced=8.0.0,fixed=8.0.32; and 9 more.
Is there a fix for CVE-2026-70183?: Yes. Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.osx-arm64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.win-arm (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet): upgrade to 8.0.32 or later; Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet): upgrade to 8.0.32 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-70183 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-70183?: Check whether you run Microsoft Asp.Net Core, Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet), Microsoft.AspNetCore.App.Runtime.linux-arm64 (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.AspNetCore.App.Runtime.linux-arm (NuGet): upgrade to 8.0.32 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm --version 8.0.32

Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet): upgrade to 8.0.32 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm64 --version 8.0.32

Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet): upgrade to 8.0.32 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-musl-arm --version 8.0.32

Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet): upgrade to 8.0.32 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 --version 8.0.32

Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet): upgrade to 8.0.32 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-musl-x64 --version 8.0.32

Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet): upgrade to 8.0.32 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.linux-x64 --version 8.0.32

Microsoft.AspNetCore.App.Runtime.osx-arm64 (NuGet): upgrade to 8.0.32 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.osx-arm64 --version 8.0.32

Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet): upgrade to 8.0.32 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.osx-x64 --version 8.0.32

Microsoft.AspNetCore.App.Runtime.win-arm (NuGet): upgrade to 8.0.32 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.win-arm --version 8.0.32

Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet): upgrade to 8.0.32 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.win-arm64 --version 8.0.32

Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet): upgrade to 8.0.32 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.win-x64 --version 8.0.32

Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet): upgrade to 8.0.32 or later

dotnet add package Microsoft.AspNetCore.App.Runtime.win-x86 --version 8.0.32

Technical details

The vulnerability is a concurrent execution race condition (CWE-362) in the Blazor AuthorizeRouteView component where asynchronous authorization results can be applied after a navigation or authorization-state change. An attacker with valid authentication credentials can trigger this race condition through network requests to bypass [Authorize] attribute enforcement. The vulnerability requires authenticated access (PR:L) and is difficult to exploit reliably (AC:H).

Affected products

Microsoft ASP.NET Core 8.0.0 through 8.0.31, 9.0.0 through 9.0.20, 10.0.0 through 10.0.12, 11.0.0-preview.1 through 11.0.0-rc.1

Identifiers

CVE-2026-70183
GHSA-494h-xx7x-5frh

Timeline

2026-10-13: disclosed

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