How severe is CVE-2021-34466?

CVE-2021-34466 has a CVSS 3.x base score of 5.7, rated medium severity. It is exploitable over physical access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-34466 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-34466?

CVE-2021-34466 primarily affects Microsoft Windows 10. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-34466?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-34466 published?

CVE-2021-34466 was published on 2021-07-16 and last updated on 2026-06-17.

CVE-2021-34466

CVE-2021-34466 is a medium-severity vulnerability in Microsoft Windows 10 with a CVSS 3.x base score of 5.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-290.

Key facts

Severity: Medium (CVSS 3.x base score 5.7)
CVSS v2: 3.6
EPSS exploit prediction: 1% (47th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-290
Affected product: Microsoft Windows 10
Published: 2021-07-16
Last modified: 2026-06-17

Description

Windows Hello Security Feature Bypass Vulnerability

Frequently asked questions

What is CVE-2021-34466?: Windows Hello Security Feature Bypass Vulnerability
How severe is CVE-2021-34466?: CVE-2021-34466 has a CVSS 3.x base score of 5.7, rated medium severity. It is exploitable over physical access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-34466 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-34466?: CVE-2021-34466 primarily affects Microsoft Windows 10. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-34466?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-34466 published?: CVE-2021-34466 was published on 2021-07-16 and last updated on 2026-06-17.

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34466

Affected products (5)

cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:21h1:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:*

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