High severity · published Aug 11, 2026
CVE-2026-66802
Windows Device Health Attestation (DHA) Remote Code Execution Vulnerability
8.1
CVSS
0.5%
EPSS
No
On KEV
Description
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Device Health Attestation (DHA) allows an unauthorized attacker to execute code over a network.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 45% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
W1
Windows 10 Version 1809 · Microsoft
10.0.17763.0 before 10.0.17763.9121 · source: vendor
W1
Windows 11 version 26H1 · Microsoft
10.0.28000.0 before 10.0.28000.2704 · source: vendor
WS
Windows Server 2019 · Microsoft
10.0.17763.0 before 10.0.17763.9121 · source: vendor, NVD
WS
Windows Server 2019 (Server Core installation) · Microsoft
10.0.17763.0 before 10.0.17763.9121 · source: vendor
WS
Windows Server 2022 · Microsoft
10.0.20348.0 before 10.0.20348.5499 · source: vendor, NVD
WS
Windows Server 2025 · Microsoft
10.0.26100.0 before 10.0.26100.33296 · source: vendor, NVD
WS
Windows Server 2025 (Server Core installation) · Microsoft
10.0.26100.0 before 10.0.26100.33296 · source: vendor
W1
Windows 10 1809 · Microsoft
before 10.0.17763.9121; before 10.0.17763.9121 · source: NVD
W1
Windows 11 26h1 · Microsoft
before 10.0.28000.2704; before 10.0.28000.2704 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-66802
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-66802
vendor-advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66802
More from Windows 10 Version 1809
9.8
CVE-2026-33824
Windows Internet Key Exchange (IKE) Service Extensions Remote Code Execution Vulnerability
8.8
CVE-2026-96951
Windows Shell Security Feature Bypass Vulnerability
8.8
CVE-2026-21510
Windows Shell Security Feature Bypass Vulnerability
8.8
CVE-2026-21513
MSHTML Framework Security Feature Bypass Vulnerability
8.8
CVE-2025-33073
Windows SMB Client Elevation of Privilege Vulnerability