CVE-2026-21218 — Improper Handling of Missing Special Element in Microsoft NET 10.0

CWE-166 — Improper Handling of Missing Special Element9 documents7 sources
Severity
7.5HIGHNVD
EPSS
0.0%
top 86.96%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
4
Microsoft NET 10.0Microsoft NET 8.0Microsoft NET 9.0+1 more
Timeline
PublishedFeb 10
Latest updateFeb 16

Description

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

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NExploitability: 3.9 | Impact: 3.6

Affected Packages4 packages

▶NVDmicrosoft/net8.0.0 — 8.0.24+2
▶CVEListV5microsoft/net_8.08.0.0 — 8.0.24
▶CVEListV5microsoft/net_9.09.0.0 — 9.0.13
▶CVEListV5microsoft/net_10.010.0.0 — 10.0.3

🔴Vulnerability Details

4
GHSA
Microsoft Security Advisory CVE-2026-21218 | .NET Security Feature Bypass Vulnerability↗2026-02-10
▶
OSV
CVE-2026-21218: Improper handling of missing special element in↗2026-02-10
▶
OSV
Microsoft Security Advisory CVE-2026-21218 | .NET Security Feature Bypass Vulnerability↗2026-02-10
▶
CVEList
.NET Spoofing Vulnerability↗2026-02-10
▶

📋Vendor Advisories

3
Ubuntu
.NET vulnerability↗2026-02-16
▶
Ubuntu
.NET vulnerability↗2026-02-11
▶
Microsoft
.NET Spoofing Vulnerability↗2026-02-10
▶

🕵️Threat Intelligence

1
Wiz
CVE-2026-21218 Impact, Exploitability, and Mitigation Steps | Wiz↗
▶
CVE-2026-21218 — Microsoft NET 10.0 vulnerability | cvebase