CVE-2026-21218HighMicrosoft CVSS 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C

Microsoft security update for CVE-2026-21218 — .NET

Published
February 10, 2026
Last Modified
—

🔗 CVE IDs covered (1)

CVE-2026-21218 →

📋 Microsoft's advisory

EchelonGraph does not copy Microsoft's advisory page: its FAQ and remediation text are not shown here. Read the advisory on https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21218. This page also shows what EchelonGraph holds for CVE-2026-21218, with the description from its CVE record, which the CVE Numbering Authority that assigned the CVE wrote: for a CVE Microsoft assigned, often in the words of Microsoft's own advisory.

🎯 Affected products9

  • .NET 10.0 installed on Linux
  • .NET 10.0 installed on Mac OS
  • .NET 10.0 installed on Windows
  • .NET 8.0 installed on Linux
  • .NET 8.0 installed on Mac OS
  • .NET 8.0 installed on Windows
  • .NET 9.0 installed on Linux
  • .NET 9.0 installed on Mac OS
  • .NET 9.0 installed on Windows

✅ Updates Microsoft lists: 3 updates

3 rows: one per KB article or update, update type and fixed build. Their details are on Microsoft's advisory.

KB articleUpdateFixed build
—Security Update10.0.3
—Security Update8.0.24
—Security Update9.0.13

🧭 EchelonGraph on CVE-2026-21218

EchelonGraph score
7.5 HIGH
CISA KEV
Not listed
Fix status
A fix is available — apply it.

Description from the CVE record (CVE.org), as published by its numbering authority

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

Published by Microsoft Corporation, the CVE Numbering Authority that assigned CVE-2026-21218, in its CVE record at CVE.org; reused under the CVE Program's Terms of Use (its licence and MITRE's copyright notice are in our Terms of Service).

🔗 References (7)