CVE-2026-21218

Publication date 10 February 2026

Last updated 11 February 2026


Ubuntu priority

Description

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

Read the notes from the security team

Status

Package Ubuntu Release Status
dotnet6 25.10 questing Not in release
25.04 plucky Not in release
24.04 LTS noble Not in release
22.04 LTS jammy
Needs evaluation
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
dotnet7 25.10 questing Not in release
25.04 plucky Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Ignored see notes
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
dotnet8 25.10 questing
Vulnerable
24.04 LTS noble
Vulnerable
22.04 LTS jammy
Vulnerable
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
dotnet9 25.10 questing
Vulnerable
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
dotnet10 25.10 questing
Vulnerable
24.04 LTS noble
Vulnerable
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release

Notes


iconstantin

.NET 7 is end of life upstream.