Vulnerability in Microsoft Windows 10 Version 1607
CVE-2026-21255
Improper access control in Windows Hyper-V allows an authorized attacker to bypass a security feature locally.
EPSS: 0.000 (11.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C.
Affected products
- Microsoft Windows 10 Version 1607 — versions 10.0.14393.0
- Microsoft Windows 10 Version 1809 — versions 10.0.17763.0
- Microsoft Windows 10 Version 21h2 — versions 10.0.19044.0
- Microsoft Windows 10 Version 22h2 — versions 10.0.19045.0
- Microsoft Windows 11 Version 22h3 — versions 10.0.22631.0
- Microsoft Windows 11 Version 23h2 — versions 10.0.22631.0
- 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
- Microsoft Windows Server 2016 — versions 10.0.14393.0
Weakness classification (CWE)
References
- Windows Hyper-V Security Feature Bypass Vulnerability (vendor-advisory, patch)
Frequently asked questions
- What is CVE-2026-21255?
- CVE-2026-21255 is a high-severity vulnerability in Microsoft Windows 10 Version 1607, classified under Improper Access Control. CVSS score: 8.8/10. Published 2026-02-10.
- How severe is CVE-2026-21255?
- High severity. CVSS v3 base score is 8.8 out of 10.