Known exploited · Microsoft
CVE-2020-1040: Microsoft Hyper-V RemoteFX vGPU Remote Code Execution Vulnerability
What it is
Microsoft Hyper-V RemoteFX vGPU contains an improper input validation vulnerability due to the host server failing to properly validate input from an authenticated user on a guest operating system. Successful exploitation allows for remote code execution on the host operating system.
- Vendor
- Microsoft
- Product
- Hyper-V RemoteFX
- Added to KEV
- November 3, 2021
- CISA due date
- May 3, 2022
- Ransomware use
- Unknown
What CISA requires
Apply updates per vendor instructions.
Forensic triage
No
What to do now
- Find every instance of Hyper-V RemoteFX you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before May 3, 2022 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
Not sure you are clear?
We check where you run it, patch or mitigate with your team, and look for signs it was already used against you.
Talk to our teamT Academy
Train the engineers who fix it
Security engineering on real hosts in the browser, every objective checked on the machine. The first two lessons of Linux 1 are free.
Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.