CVE-2026-66799 PUBLISHED

Windows Key Guard Elevation of Privilege Vulnerability

Assigner: microsoft
Reserved: 27.07.2026 Published: 11.08.2026 Updated: 11.08.2026

Heap-based buffer overflow in Windows Key Guard allows an authorized attacker to elevate privileges locally.

Metrics

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
CVSS Score: 7.8

Product Status

Vendor Microsoft
Product Windows 10 Version 1607
Versions
  • affected from 10.0.14393.0 to 10.0.14393.9418 (excl.)
Vendor Microsoft
Product Windows 10 Version 1809
Versions
  • affected from 10.0.17763.0 to 10.0.17763.9115 (excl.)
Vendor Microsoft
Product Windows 10 Version 21H2
Versions
  • affected from 10.0.19044.0 to 10.0.19044.7663 (excl.)
Vendor Microsoft
Product Windows 10 Version 22H2
Versions
  • affected from 10.0.19045.0 to 10.0.19045.7663 (excl.)
Vendor Microsoft
Product Windows 11 version 23H2
Versions
  • affected from 10.0.22631.0 to 10.0.22631.7517 (excl.)
Vendor Microsoft
Product Windows 11 Version 23H2
Versions
  • affected from 10.0.22631.0 to 10.0.22631.7517 (excl.)
Vendor Microsoft
Product Windows 11 Version 24H2
Versions
  • affected from 10.0.26100.0 to 10.0.26100.9168 (excl.)
Vendor Microsoft
Product Windows 11 Version 25H2
Versions
  • affected from 10.0.26200.0 to 10.0.26200.9168 (excl.)
Vendor Microsoft
Product Windows 11 version 26H1
Versions
  • affected from 10.0.28000.0 to 10.0.28000.2704 (excl.)
Vendor Microsoft
Product Windows Server 2012
Versions
  • affected from 6.2.9200.0 to 6.2.9200.26280 (excl.)
Vendor Microsoft
Product Windows Server 2012 (Server Core installation)
Versions
  • affected from 6.2.9200.0 to 6.2.9200.26280 (excl.)
Vendor Microsoft
Product Windows Server 2012 R2
Versions
  • affected from 6.3.9600.0 to 6.3.9600.23338 (excl.)
Vendor Microsoft
Product Windows Server 2012 R2 (Server Core installation)
Versions
  • affected from 6.3.9600.0 to 6.3.9600.23338 (excl.)
Vendor Microsoft
Product Windows Server 2016
Versions
  • affected from 10.0.14393.0 to 10.0.14393.9418 (excl.)
Vendor Microsoft
Product Windows Server 2016 (Server Core installation)
Versions
  • affected from 10.0.14393.0 to 10.0.14393.9418 (excl.)
Vendor Microsoft
Product Windows Server 2019
Versions
  • affected from 10.0.17763.0 to 10.0.17763.9115 (excl.)
Vendor Microsoft
Product Windows Server 2019 (Server Core installation)
Versions
  • affected from 10.0.17763.0 to 10.0.17763.9115 (excl.)
Vendor Microsoft
Product Windows Server 2022
Versions
  • affected from 10.0.20348.0 to 10.0.20348.5499 (excl.)
Vendor Microsoft
Product Windows Server 2025
Versions
  • affected from 10.0.26100.0 to 10.0.26100.33296 (excl.)
Vendor Microsoft
Product Windows Server 2025 (Server Core installation)
Versions
  • affected from 10.0.26100.0 to 10.0.26100.33296 (excl.)

References

Problem Types