Vulnerability in Microsoft Windows 10 1607
CVE-2026-21255
Improper access control in Windows Hyper-V allows an authorized attacker to bypass a security feature locally.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.004 (29.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000
Affected products
- Microsoft Windows 10 1607
- Microsoft Windows 10 1809
- Microsoft Windows 10 21h2
- Microsoft Windows 10 22h2
- 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 23h2
- Microsoft Windows 11 24h2
Weakness classification (CWE)
References
- Windows Hyper-V Security Feature Bypass Vulnerability (vendor-advisory, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-21255?
- CVE-2026-21255 is a high-severity vulnerability in Microsoft Windows 10 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.