How severe is CVE-2018-8221?

CVE-2018-8221 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2018-8221 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-8221?

CVE-2018-8221 primarily affects Microsoft Windows 10. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-8221?

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

When was CVE-2018-8221 published?

CVE-2018-8221 was published on 2018-06-14 and last updated on 2026-06-17.

CVE-2018-8221

CVE-2018-8221 is a medium-severity vulnerability in Microsoft Windows 10 with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 4.6
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Windows 10
Published: 2018-06-14
Last modified: 2026-06-17

Description

A security feature bypass vulnerability exists in Device Guard that could allow an attacker to inject malicious code into a Windows PowerShell session, aka "Device Guard Code Integrity Policy Security Feature Bypass Vulnerability." This affects Windows Server 2016, Windows 10, Windows 10 Servers. This CVE ID is unique from CVE-2018-8201, CVE-2018-8211, CVE-2018-8212, CVE-2018-8215, CVE-2018-8216, CVE-2018-8217.

Frequently asked questions

What is CVE-2018-8221?: A security feature bypass vulnerability exists in Device Guard that could allow an attacker to inject malicious code into a Windows PowerShell session, aka "Device Guard Code Integrity Policy Security Feature Bypass Vulnerability." This affects Windows Server 2016, Windows 10, Windows 10 Servers. This CVE ID is unique from CVE-2018-8201, CVE-2018-8211, CVE-2018-8212, CVE-2018-8215, CVE-2018-8216, CVE-2018-8217.
How severe is CVE-2018-8221?: CVE-2018-8221 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2018-8221 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-8221?: CVE-2018-8221 primarily affects Microsoft Windows 10. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-8221?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-8221 published?: CVE-2018-8221 was published on 2018-06-14 and last updated on 2026-06-17.

References

Affected products (8)

cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1703:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1709:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10:1803:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:1709:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:1803:*:*:*:*:*:*:*

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