How severe is CVE-2018-8434?

CVE-2018-8434 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2018-8434 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-8434?

CVE-2018-8434 primarily affects Microsoft Windows 10. In total, 14 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-8434?

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

When was CVE-2018-8434 published?

CVE-2018-8434 was published on 2018-09-13 and last updated on 2026-06-17.

CVE-2018-8434

CVE-2018-8434 is a medium-severity vulnerability in Microsoft Windows 10 with a CVSS 3.x base score of 5.4. 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-20.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 5.2
EPSS exploit prediction: 3% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Microsoft Windows 10
Published: 2018-09-13
Last modified: 2026-06-17

Description

An information disclosure vulnerability exists when Windows Hyper-V on a host operating system fails to properly validate input from an authenticated user on a guest operating system, aka "Windows Hyper-V Information Disclosure Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.

Frequently asked questions

What is CVE-2018-8434?: An information disclosure vulnerability exists when Windows Hyper-V on a host operating system fails to properly validate input from an authenticated user on a guest operating system, aka "Windows Hyper-V Information Disclosure Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.
How severe is CVE-2018-8434?: CVE-2018-8434 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2018-8434 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-8434?: CVE-2018-8434 primarily affects Microsoft Windows 10. In total, 14 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-8434?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-8434 published?: CVE-2018-8434 was published on 2018-09-13 and last updated on 2026-06-17.

References

Affected products (14)

cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10:1703:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10:1709:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10:1803:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:rt:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:sp2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2012:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
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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