CVE-2021-36955 Microsoft Windows Common Log File System (CLFS) Driver Privilege Escalation
An attacker can exploit the Windows Common Log File System Driver to gain elevated privileges on affected Windows systems.
- Exploited in the wild
- Since 3 Nov 2021
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-36955?
CVE-2021-36955 is a high-severity vulnerability in Microsoft Windows 10 1507, published on 15 Sep 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Windows Common Log File System Driver Elevation of Privilege Vulnerability
Which versions are affected by CVE-2021-36955?
It affects 17 products.
Products include Microsoft Windows 10 1507, Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 1909, Microsoft Windows 10 2004, Microsoft Windows 10 20h2 and 11 more.
How do I fix CVE-2021-36955?
No fix has been published for CVE-2021-36955 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 17 Nov 2021.
Is CVE-2021-36955 being exploited?
Yes. Attackers have exploited CVE-2021-36955 in the wild since at least 3 Nov 2021, including in ransomware campaigns.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Microsoft Windows 10 1507
- CVE-2017-8543 Microsoft Windows Search Remote Code Execution
- CVE-2025-33053 Microsoft Windows External Control of File Name or Path
- CVE-2025-33073 Microsoft Windows SMB Client Improper Access Control
- CVE-2024-49039 Microsoft Windows Task Scheduler Privilege Escalation
- CVE-2024-43461 Microsoft Windows MSHTML Platform Spoofing
Sources
Also known as GHSA-g26f-6mx8-j24w.