How severe is CVE-2020-1040?

CVE-2020-1040 has a CVSS score of 9/10, rated CRITICAL. Immediate patching is strongly recommended.

Which products are affected by CVE-2020-1040?

Affected package information for CVE-2020-1040 is not yet fully mapped. Check the official advisory links for details.

How do I patch CVE-2020-1040?

No patch has shipped for CVE-2020-1040 yet — track the microsoft windows server 2008 advisory for a fixed release and apply the workarounds below in the meantime.

How do I detect CVE-2020-1040 across my infrastructure?

Inventory every microsoft windows server 2008 deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

How do I mitigate CVE-2020-1040 if there is no patch (or I can't update yet)?

Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

How does O3 Security protect against CVE-2020-1040?

O3 detects and blocks CVE-2020-1040 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Is CVE-2020-1040 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2020-1040, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2020-1040?

CVE-2020-1040 has an EPSS (Exploit Prediction Scoring System) score of 6.9%, placing it in the 93th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

Is CVE-2020-1040 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2020-1040 (Microsoft Hyper-V RemoteFX vGPU Remote Code Execution Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-05-03. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2020-1040?

CVE-2020-1040 is classified as Improper Input Validation (CWE-20). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2020-1040?

CVE-2020-1040 affects microsoft windows server 2008 (1 version, e.g. r2); microsoft windows server 2012 (1 version, e.g. r2); microsoft windows server 2016. Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2020-1040 published, and has it been updated?

CVE-2020-1040 was published on July 14, 2020 and was last updated on June 17, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2021-11-03 — agencies required to remediate by 2022-05-03

CVE-2020-1040

CRITICAL

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…

Published

Jul 14, 2020

Updated

Jun 17, 2026

Affected

0 pkgs

Patched

None yet

Exploits

1 known

EPSS Exploitation Probability

via FIRST.org ↗

6.9%probability of exploitation in next 30 days

Lower Risk93th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

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.

Affected Products

3 products · 4 configurations

windows server 2008microsoft

1 version

windows server 2012microsoft

1 version

windows server 2016microsoft

all

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

A remote code execution vulnerability exists when Hyper-V RemoteFX vGPU …

cisa.govCISAJul 2021

Detection & mitigation playbook

Vendor / appliance

Detect
Inventory every microsoft windows server 2008 deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2020-1040 yet — track the microsoft windows server 2008 advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2020-1040 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2020-1040. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Runtime Protection

Is CVE-2020-1040 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2020-1040 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.

Protect my workloads How runtime protection works

CVE-2020-1040

EPSS Exploitation Probability

Description

Affected Products

Detection & mitigation playbook

Detect

Remediation status

Mitigate without a patch

How O3 protects you

Frequently Asked Questions

Is CVE-2020-1040 being exploited in your environment?