CVE-2026-66804

Microsoft Windows Cross Device Service Elevation of Privilege Vulnerability

Improper access control in Windows Cross Device Service allows an authorized attacker to elevate privileges locally.

Affected

Microsoft · Windows 10 Version 22H2 · Windows 11 Version 24H2 · Windows 11 Version 25H2 · Windows 11 version 26H1

CVSS v3.1 MICROSOFT

7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

0.30% chance of exploitation in the next 30 days, 21st percentile

Published

2026-08-11

Updated

2026-10-08

Proof-of-concept exploits (3)

• DavidCarliez/CVE-2026-66804-CrossDevice-LPE15★ · 2026-08-11
• CypherHippie/CVE-2026-668041★ · 2026-08-18
• Rat5ak/CVE-2026-66804-CrossDevice-Service-EoP24★ · 2026-08-13

Security advisories

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66804

References

• CVE Record
• NVD entry

Related

• CVE-2019-9702
• CVE-2026-49176
• CVE-2026-50454
• CVE-2026-54992
• CVE-2026-58635
• CVE-2026-34486