CVE-2026-21218
February 10, 2026
Improper handling of missing special element in .NET allows an unauthorized attacker to perform spoofing over a network.
Affected Packages
https://github.com/dotnet/runtime.git (GITHUB):
Affected version(s) >=v9.0.0 <v9.0.13Fix Suggestion:
Update to version v9.0.13https://github.com/dotnet/runtime.git (GITHUB):
Affected version(s) >=v10.0.0 <v10.0.3Fix Suggestion:
Update to version v10.0.3https://github.com/dotnet/runtime.git (GITHUB):
Affected version(s) >=v8.0.0 <v8.0.24Fix Suggestion:
Update to version v8.0.24system.security.cryptography.cose (NUGET):
Affected version(s) >=10.0.0 <10.0.3Fix Suggestion:
Update to version 10.0.3system.security.cryptography.cose (NUGET):
Affected version(s) >=9.0.0 <9.0.13Fix Suggestion:
Update to version 9.0.13system.security.cryptography.cose (NUGET):
Affected version(s) >=8.0.0 <8.0.2Fix Suggestion:
Update to version 8.0.2Related Resources (4)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Exploit Maturity
UNPROVEN
Weakness Type (CWE)
Improper Handling of Missing Special Element
EPSS
Base Score:
0.03
