CVE-2026-66804 — HIGH (7.8)

Q: What is CVE-2026-66804?

CVE-2026-66804 is a vulnerability with a CVSS score of 7.8 (HIGH). Improper access control in Windows Cross Device Service allows an authorized attacker to elevate privileges locally.

Q: How severe is CVE-2026-66804?

CVE-2026-66804 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.

Q: Is there a patch for CVE-2026-66804?

Check the references section above for vendor advisories and patch information. Affected products include: Microsoft Windows 10 22H2, Microsoft Windows 11 24H2, Microsoft Windows 11 25H2, Microsoft Windows 11 26H1.

Vulnerability Description

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

CVSS Score

7.8

HIGH

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

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
Microsoft	Windows 10 22H2	< 10.0.19045.7663
Microsoft	Windows 11 24H2	< 10.0.26100.9106
Microsoft	Windows 11 25H2	< 10.0.26200.9106
Microsoft	Windows 11 26H1	< 10.0.28000.2704

Related Weaknesses (CWE)

CWE-284

References

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

FAQ

What is CVE-2026-66804?

CVE-2026-66804 is a vulnerability with a CVSS score of 7.8 (HIGH). Improper access control in Windows Cross Device Service allows an authorized attacker to elevate privileges locally.

How severe is CVE-2026-66804?

CVE-2026-66804 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-66804?

Check the references section above for vendor advisories and patch information. Affected products include: Microsoft Windows 10 22H2, Microsoft Windows 11 24H2, Microsoft Windows 11 25H2, Microsoft Windows 11 26H1.