Name: CVE-2026-21218: Improper Handling of Missing Special Element
Creator: Rapid7
Published: 2026-02-10T00:00:00.000Z
License: https://www.rapid7.com/legal/website-terms-of-use/
Keywords: CVE, CVE-2026-21218, CVSS 7.5, EPSS 0.01012

Improper handling of missing special element in .NET allows an unauthorized attacker to perform spoofing over a network.

CVSS Details

CVSS 3.1 Base Score: 7.5
CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C)

Covered by Rapid7

Product	Vendor Advisory	Solution File	Added	Published
Alpine Linux	—	Upgrade dotnet10-runtimeUpgrade dotnet9-runtimeUpgrade dotnet8-runtime	Feb 23, 2026	Feb 10, 2026
Microsoft Dot_net	—	Upgrade .NET Runtime 10.0 to laterUpgrade .NET Runtime 9.0 to laterUpgrade .NET Runtime 8.0 to later	Jul 28, 2026	Feb 10, 2026
Ubuntu	—	Upgrade dotnet-runtime-10.0Upgrade dotnet8Upgrade dotnet-host-8.0Upgrade dotnet-host-10.0Upgrade dotnet-runtime-8.0Upgrade aspnetcore-runtime-9.0Upgrade dotnet-sdk-aot-9.0Upgrade dotnet-sdk-aot-10.0Upgrade dotnet-hostfxr-10.0Upgrade dotnet9Upgrade dotnet-sdk-9.0Upgrade dotnet-hostfxr-9.0Upgrade aspnetcore-runtime-8.0Upgrade dotnet-hostfxr-8.0Upgrade aspnetcore-runtime-10.0Upgrade dotnet-host-9.0Upgrade dotnet10Upgrade dotnet-sdk-8.0Upgrade dotnet-sdk-10.0Upgrade dotnet-runtime-9.0	Feb 13, 2026	Feb 11, 2026
Vmware Photon_os	—	Use 'tdnf update' to upgrade all packages to the latest version.	May 27, 2026	Feb 10, 2026

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CVSS Details

Covered by Rapid7

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