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Microsoft Security Response CenterCVE-2026-40372

ASP.NET Core Elevation of Privilege Vulnerability

HighVendor CVSS 9.1 / 10 1 CVE Published Apr 21, 2026 at 7:00 AM UTC

Summary

Improper verification of cryptographic signature in ASP.NET Core allows an unauthorized attacker to elevate privileges over a network.

Products covered

  • ASP.NET Core 10.0

  • Microsoft Visual Studio 2026 version 18.5

Remediation

Release Notes Install KB5091596.

Vendor-listed fixes

  • 10.0.7

  • 18.5.2

CVEs in this advisory 1

Updates

  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.