How severe is CVE-2020-1040?

CVE-2020-1040 has a CVSS 3.x base score of 9.0, rated critical severity. It is exploitable over an adjacent network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-1040 being actively exploited?

Yes. CVE-2020-1040 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2021-11-03, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2020-1040?

CVE-2020-1040 primarily affects Microsoft Windows Server 2008. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-1040?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2020-1040 have an EU (EUVD) identifier?

Yes. CVE-2020-1040 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-11934. It is also flagged as exploited in the EUVD (since 2021-11-03).

When was CVE-2020-1040 published?

CVE-2020-1040 was published on 2020-07-14 and last updated on 2026-06-17.

CVE-2020-1040

CVE-2020-1040 is a critical-severity vulnerability in Microsoft Windows Server 2008 with a CVSS 3.x base score of 9.0. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2021-11-03). The underlying weakness is classified as CWE-20.

Key facts

Severity: Critical (CVSS 3.x base score 9.0)
CVSS v2: 7.7
EPSS exploit prediction: 7% (93rd percentile)
Actively exploited: Yes — listed in CISA KEV (added 2021-11-03)
EU (EUVD) id: EUVD-2020-11934
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2021-11-03)
Weakness: CWE-20
Affected product: Microsoft Windows Server 2008
Published: 2020-07-14
Last modified: 2026-06-17

Description

A remote code execution vulnerability exists when Hyper-V RemoteFX vGPU on a host server fails to properly validate input from an authenticated user on a guest operating system, aka 'Hyper-V RemoteFX vGPU Remote Code Execution Vulnerability'. This CVE ID is unique from CVE-2020-1032, CVE-2020-1036, CVE-2020-1041, CVE-2020-1042, CVE-2020-1043.

Frequently asked questions

What is CVE-2020-1040?: A remote code execution vulnerability exists when Hyper-V RemoteFX vGPU on a host server fails to properly validate input from an authenticated user on a guest operating system, aka 'Hyper-V RemoteFX vGPU Remote Code Execution Vulnerability'. This CVE ID is unique from CVE-2020-1032, CVE-2020-1036, CVE-2020-1041, CVE-2020-1042, CVE-2020-1043.
How severe is CVE-2020-1040?: CVE-2020-1040 has a CVSS 3.x base score of 9.0, rated critical severity. It is exploitable over an adjacent network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-1040 being actively exploited?: Yes. CVE-2020-1040 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2021-11-03, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2020-1040?: CVE-2020-1040 primarily affects Microsoft Windows Server 2008. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-1040?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2020-1040 have an EU (EUVD) identifier?: Yes. CVE-2020-1040 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-11934. It is also flagged as exploited in the EUVD (since 2021-11-03).
When was CVE-2020-1040 published?: CVE-2020-1040 was published on 2020-07-14 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:o:microsoft:windows_server_2008:r2:*:*:*:*:*:x64:*
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:-:*:*:*:*:*:*:*

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