CVE-2026-27906: Windows Hello Security Feature Bypass Vulnerability

Severity: medium (CVSS 4.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-14 · updated 2026-10-26
Weakness: CWE-20

Description

Improper input validation in Windows Hello allows an authorized attacker to bypass a security feature locally.

Affected products

Microsoft Windows 10: before 10.0.19044.7184 — fixed in 10.0.19044.7184
Microsoft Windows 10: before 10.0.19045.7184 — fixed in 10.0.19045.7184
Microsoft Windows 11: before 10.0.22631.6936 — fixed in 10.0.22631.6936
Microsoft Windows 11: before 10.0.26100.8246 — fixed in 10.0.26100.8246
Microsoft Windows 11 25H2: before 10.0.26200.8246 — fixed in 10.0.26200.8246
Microsoft Windows 11 version 26H1: before 10.0.28000.1836 — fixed in 10.0.28000.1836
Microsoft Windows 10: from 10.0.19044.0 before 10.0.19044.7184 — fixed in 10.0.19044.7184
Microsoft Windows 10: from 10.0.19045.0 before 10.0.19045.7184 — fixed in 10.0.19045.7184
Microsoft Windows 11: from 10.0.22631.0 before 10.0.22631.6936 — fixed in 10.0.22631.6936
Microsoft Windows 11: from 10.0.26100.0 before 10.0.26100.8246 — fixed in 10.0.26100.8246
Microsoft Windows 11 25H2: from 10.0.26200.0 before 10.0.26200.8246 — fixed in 10.0.26200.8246
Microsoft Windows 11 version 26H1: from 10.0.28000.0 before 10.0.28000.1836 — fixed in 10.0.28000.1836

How to fix

Upgrade to a fixed version: Microsoft Windows 10 10.0.19044.7184; Microsoft Windows 10 10.0.19045.7184; Microsoft Windows 11 10.0.22631.6936; Microsoft Windows 11 10.0.26100.8246; Microsoft Windows 11 25H2 10.0.26200.8246; Microsoft Windows 11 version 26H1 10.0.28000.1836; Microsoft Windows 10 10.0.19044.7184; Microsoft Windows 10 10.0.19045.7184; Microsoft Windows 11 10.0.22631.6936; Microsoft Windows 11 10.0.26100.8246; Microsoft Windows 11 25H2 10.0.26200.8246; Microsoft Windows 11 version 26H1 10.0.28000.1836. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-27906

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