CVE-2026-21218

HIGH

.NET 8.0.0-8.0.23, 9.0.0-9.0.12, 10.0.0-10.0.2 - Spoofing via Missing Special Element Handling

Title source: llm
STIX 2.1

Description

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

References (1)

Core 1
Core References

Scores

CVSS v3 7.5
EPSS 0.0004
EPSS Percentile 13.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-166
Status published
Products (5)
microsoft/.net 8.0.0 - 8.0.24
Microsoft/.NET 10.0 10.0.0 - 10.0.3
Microsoft/.NET 8.0 8.0.0 - 8.0.24
Microsoft/.NET 9.0 9.0.0 - 9.0.13
nuget/System.Security.Cryptography.Cose 8.0.0 - 8.0.2NuGet
Published Feb 10, 2026
Tracked Since Feb 18, 2026