CVE-2026-70183 ASP.NET Core Elevation of Privilege Vulnerability

High 7.5 Published Updated

An authorized attacker can elevate privileges via a race condition in ASP.NET Core shared resource handling.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2026-70183?

CVE-2026-70183 is a high-severity vulnerability in Microsoft ASP.NET Core 10.0, published on 13 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Concurrent execution using shared resource with improper synchronization ('race condition') in ASP.NET Core allows an authorized attacker to elevate privileges over a network.

Weakness: CWE-362

Which versions are affected by CVE-2026-70183?

40 open source packages ship an affected version, including Microsoft.AspNetCore.App.Runtime.linux-arm, Microsoft.AspNetCore.App.Runtime.linux-arm64 and Microsoft.AspNetCore.App.Runtime.linux-musl-arm.

PackageAffectedFixed in
Microsoft.AspNetCore.App.Runtime.linux-arm NuGetFrom 10.0.010.0.13
Microsoft.AspNetCore.App.Runtime.linux-arm NuGetFrom 10.0.010.0.13
Microsoft.AspNetCore.App.Runtime.linux-arm NuGetFrom 11.0.0-preview.111.0.0-rc.2
Microsoft.AspNetCore.App.Runtime.linux-arm NuGetFrom 11.0.0-preview.111.0.0-rc.2
Microsoft.AspNetCore.App.Runtime.linux-arm NuGetFrom 8.0.08.0.32
Microsoft.AspNetCore.App.Runtime.linux-arm NuGetFrom 8.0.08.0.32
34 more packages
Microsoft.AspNetCore.App.Runtime.linux-arm NuGetFrom 9.0.09.0.21
Microsoft.AspNetCore.App.Runtime.linux-arm NuGetFrom 9.0.09.0.21
Microsoft.AspNetCore.App.Runtime.linux-arm64 NuGetFrom 10.0.010.0.13
Microsoft.AspNetCore.App.Runtime.linux-arm64 NuGetFrom 10.0.010.0.13
Microsoft.AspNetCore.App.Runtime.linux-arm64 NuGetFrom 11.0.0-preview.111.0.0-rc.2
Microsoft.AspNetCore.App.Runtime.linux-arm64 NuGetFrom 11.0.0-preview.111.0.0-rc.2
Microsoft.AspNetCore.App.Runtime.linux-arm64 NuGetFrom 8.0.08.0.32
Microsoft.AspNetCore.App.Runtime.linux-arm64 NuGetFrom 8.0.08.0.32
Microsoft.AspNetCore.App.Runtime.linux-arm64 NuGetFrom 9.0.09.0.21
Microsoft.AspNetCore.App.Runtime.linux-arm64 NuGetFrom 9.0.09.0.21
Microsoft.AspNetCore.App.Runtime.linux-musl-arm NuGetFrom 10.0.010.0.13
Microsoft.AspNetCore.App.Runtime.linux-musl-arm NuGetFrom 10.0.010.0.13
Microsoft.AspNetCore.App.Runtime.linux-musl-arm NuGetFrom 11.0.0-preview.111.0.0-rc.2
Microsoft.AspNetCore.App.Runtime.linux-musl-arm NuGetFrom 11.0.0-preview.111.0.0-rc.2
Microsoft.AspNetCore.App.Runtime.linux-musl-arm NuGetFrom 8.0.08.0.32
Microsoft.AspNetCore.App.Runtime.linux-musl-arm NuGetFrom 8.0.08.0.32
Microsoft.AspNetCore.App.Runtime.linux-musl-arm NuGetFrom 9.0.09.0.21
Microsoft.AspNetCore.App.Runtime.linux-musl-arm NuGetFrom 9.0.09.0.21
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 NuGetFrom 10.0.010.0.13
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 NuGetFrom 10.0.010.0.13
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 NuGetFrom 11.0.0-preview.111.0.0-rc.2
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 NuGetFrom 11.0.0-preview.111.0.0-rc.2
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 NuGetFrom 8.0.08.0.32
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 NuGetFrom 8.0.08.0.32
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 NuGetFrom 9.0.09.0.21
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 NuGetFrom 9.0.09.0.21
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 NuGetFrom 10.0.010.0.13
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 NuGetFrom 10.0.010.0.13
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 NuGetFrom 11.0.0-preview.111.0.0-rc.2
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 NuGetFrom 11.0.0-preview.111.0.0-rc.2
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 NuGetFrom 8.0.08.0.32
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 NuGetFrom 8.0.08.0.32
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 NuGetFrom 9.0.09.0.21
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 NuGetFrom 9.0.09.0.21

How do I fix CVE-2026-70183?

Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm to a fixed version for your release line: 10.0.13, 11.0.0-rc.2, 8.0.32 or 9.0.21.

Is CVE-2026-70183 being exploited?

There is no known exploitation of CVE-2026-70183 in the wild and no public exploit code.

Sources

Also known as CLEANSTART-2026-UL53365, GHSA-494h-xx7x-5frh, UBUNTU-CVE-2026-70183.

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