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Microsoft Security Response CenterCVE-2026-47303

ASP.NET Core Elevation of Privilege Vulnerability

Authentication bypass by assumed-immutable data in ASP.NET Core allows an authorized attacker to elevate privileges over a network.

Read the vendor bulletin Get alerts for NET 10.0 installed on Linux
8.8CVSS out of 10High severity
Scope

What the vendor says is affected

  • .NET 10.0 installed on Linux
  • .NET 10.0 installed on Mac OS
  • .NET 8.0 installed on Windows
  • .NET 8.0 installed on Linux
  • .NET 9.0 installed on Linux
  • .NET 8.0 installed on Mac OS
  • .NET 9.0 installed on Mac OS
  • .NET 9.0 installed on Windows
  • Microsoft Visual Studio 2022 version 17.12
  • Microsoft Visual Studio 2022 version 17.14
  • Microsoft Visual Studio 2026 version 18.7

Versions the vendor lists as fixed

  • 10.0.10
  • 8.0.29
  • 9.0.18
  • 17.12.22
  • 17.14.36
  • 18.7.4
Next step

What the vendor recommends

Release Notes Install KB5104034. Install KB5104032. Install KB5104033.

Review the complete instructions on the vendor's site
Timeline

When this advisory changed

  1. Published by Microsoft Security Response Center

    The publication date reported by the vendor.

  2. Updated by Microsoft Security Response Center

    The vendor changed the advisory after it was first published.

  3. Added to SecurityAlert

    We collected the advisory from the official source.

  4. Confirmed at the source

    Our collector saw this advisory during a later source check.

Vulnerabilities

CVEs named in this advisory

CVE-2026-47303View CVSS, KEV, EPSS, and threat context
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