Windows Device Health Attestation (DHA) Remote Code Execution Vulnerability

published 2026-08-11 2 mo ago modified 2026-10-30 9 d ago also EUVD-2026-56746

cvss: 8.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits: 0; none known

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.

Patch / fix

fixed in 7 links 1

Microsoft Windows 10 Version 1809 10.0.17763.9121
Microsoft Windows 11 version 26H1 10.0.28000.2704
Microsoft Windows Server 2019 10.0.17763.9121
Microsoft Windows Server 2019 (Server Core installation) 10.0.17763.9121
Microsoft Windows Server 2022 10.0.20348.5499
Microsoft Windows Server 2025 10.0.26100.33296
Microsoft Windows Server 2025 (Server Core installation) 10.0.26100.33296

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66802 advisory

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 3 mo ago (2026-08-06)

Exploit prediction

0.54% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
CNA	3.1	8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Microsoft Windows 10 Version 1809
Microsoft Windows 11 version 26H1
Microsoft Windows Server 2019
Microsoft Windows Server 2019 (Server Core installation)
Microsoft Windows Server 2022
Microsoft Windows Server 2025
Microsoft Windows Server 2025 (Server Core installation)

Classification

Weakness

CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
CWE-416 Use After Free

References

msrc.microsoft.com /update-guide/vulnerability/CVE-2026-66802
vendor-advisory, patch

Sources

CVE List CVE-2026-66802
NVD CVE-2026-66802

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary