CVE-2026-44805: Windows Network Controller (NC) Host Agent Denial of Service Vulnerability

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-09 · updated 2026-09-24
Weakness: CWE-416

Description

Use after free in Windows Network Controller (NC) Host Agent allows an authorized attacker to deny service locally.

Affected products

Microsoft Windows Server 2019: before 10.0.17763.8880 — fixed in 10.0.17763.8880
Microsoft Windows Server 2022: before 10.0.20348.5256 — fixed in 10.0.20348.5256
Microsoft Windows Server 2025: before 10.0.26100.32995 — fixed in 10.0.26100.32995
Microsoft Windows Server 2019: from 10.0.17763.0 before 10.0.17763.8880 — fixed in 10.0.17763.8880
Microsoft Windows Server 2022: from 10.0.20348.0 before 10.0.20348.5256 — fixed in 10.0.20348.5256
Microsoft Windows Server 2025: from 10.0.26100.0 before 10.0.26100.32995 — fixed in 10.0.26100.32995

How to fix

Upgrade to a fixed version: Microsoft Windows Server 2019 10.0.17763.8880; Microsoft Windows Server 2022 10.0.20348.5256; Microsoft Windows Server 2025 10.0.26100.32995; Microsoft Windows Server 2019 10.0.17763.8880; Microsoft Windows Server 2022 10.0.20348.5256; Microsoft Windows Server 2025 10.0.26100.32995. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-44805

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