CVE-2026-66802: Windows Device Health Attestation (DHA) Remote Code Execution Vulnerability
This Microsoft advisory covers CVE-2026-66802 in Windows Server 2019, Windows Server 2022 and Windows Server 2025.
- CVE-2026-66802
Key facts
- Vendor rating
- High, CVSS 8.1
- CISA KEV
- Not listed (catalogue checked )
- Affected
- Windows 10 Version 1809 10.0.17763.0 before 10.0.17763.9115; Windows 11 version 26H1 10.0.28000.0 before 10.0.28000.2704; Windows Server 2019 10.0.17763.0 before 10.0.17763.9115 and 4 more below
- Fixed in
- KB5120238 (build 10.0.17763.9121), KB5120242 (build 10.0.20348.5499), KB5120229 (build 10.0.20348.5440) and 3 more below
- Source published
- Listed by VulniPulse
Compiled by VulniPulse from the linked sources. How records are collected and checked.
Affected products & platforms
Description
Windows Device Health Attestation (DHA) Remote Code Execution Vulnerability
Affected products named by the advisory: Windows Server 2019; Windows Server 2022; Windows Server 2025.
Text from the source record.
- Windows 10 Version 1809 10.0.17763.0 before 10.0.17763.9115
- Windows 11 version 26H1 10.0.28000.0 before 10.0.28000.2704
- Windows Server 2019 10.0.17763.0 before 10.0.17763.9115
- Windows Server 2019 (Server Core installation) 10.0.17763.0 before 10.0.17763.9115
- Windows Server 2022 10.0.20348.0 before 10.0.20348.5499
- Windows Server 2025 10.0.26100.0 before 10.0.26100.33296
- Windows Server 2025 (Server Core installation) 10.0.26100.0 before 10.0.26100.33296
Official advisory · high-confidence parse· fetched ·verify at source
How to fix CVE-2026-66802
Upgrade to a fixed release named by Microsoft:
- KB5120238 (build 10.0.17763.9121)
- KB5120242 (build 10.0.20348.5499)
- KB5120229 (build 10.0.20348.5440)
- KB5120233 (build 10.0.26100.33296)
- KB5120228 (build 10.0.26100.33222)
- KB5121000 (build 10.0.28000.2704)
Vendor guidance
- Install the applicable security update for your platform: KB5120238, KB5120242, KB5120229, KB5120233, KB5120228, KB5121000 (see the Microsoft Update Catalog).
End-of-life dates for Windows Server
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Microsoft Server advisories, August 2026All Microsoft Server advisories
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