Vulnerability in Microsoft Windows 10 22h2
CVE-2026-66804
Improper access control in Windows Cross Device Service allows an authorized attacker to elevate privileges locally.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.003 (20.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 20.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.053 · newest: 0.003 · change: -0.050
Affected products
- Microsoft Windows 10 22h2
- Microsoft Windows 10 Version 22h2 — versions 10.0.19045.0
- Microsoft Windows 11 24h2
- Microsoft Windows 11 25h2
- Microsoft Windows 11 26h1
- Microsoft Windows 11 Version 24h2 — versions 10.0.26100.0
- Microsoft Windows 11 Version 25h2 — versions 10.0.26200.0
- Microsoft Windows 11 Version 26h1 — versions 10.0.28000.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- Microsoft Windows Cross Device Service Elevation of Privilege Vulnerability (vendor-advisory, Patch, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-66804?
- CVE-2026-66804 is a high-severity vulnerability in Microsoft Windows 10 22h2, classified under Improper Access Control. CVSS score: 7.8/10. Published 2026-08-11.
- How severe is CVE-2026-66804?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2026-66804 known to be exploited?
- 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.