Microsoft Azure Attestation service and Device Health Attestation Service
CVE-2026-66802 — Windows Device Health Attestation (DHA) Remote Code Execution Vulnerability
Executive Summary
Concurrent execution using shared resource with improper synchronization ('race condition') in Microsoft Azure Attestation service and Device Health Attestation Service allows an unauthorized attacker to execute code over a network.
Overview
8.1
CVSS HIGH
Critical
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
CVSS Vector
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
ATTACK VECTOR
Network
ATTACK COMPLEXITY
High
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 7.1
EPSS Score
0.0036
probability of exploitation in the next 30 days
0.29 percentile - updated 2026-08-14
View on FIRST.org
Affected Products
6 affected products
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Windows 10 Version 1809 for 32-bit Systems | 5120238 (Security Update) |
Critical | Remote Code Execution | Yes |
| Windows 10 Version 1809 for x64-based Systems | 5120238 (Security Update) |
Critical | Remote Code Execution | Yes |
| Windows 11 Version 26H1 for ARM64-based Systems | 5121000 (Security Update) |
Critical | Remote Code Execution | Yes |
| Windows 11 version 26H1 for x64-based Systems | 5121000 (Security Update) |
Critical | Remote Code Execution | Yes |
| Windows Server 2019 | 5120238 (Security Update) |
Critical | Remote Code Execution | Yes |
| Windows Server 2019 (Server Core installation) | 5120238 (Security Update) |
Critical | Remote Code Execution | Yes |
Patches
2 patches
| Article | Type | Restart |
|---|---|---|
5120238 |
Security Update | Yes |
5121000 |
Security Update | Yes |
Known Exploits
No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.
Acknowledgments
Anonymous
References
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