Actively exploited
Listed in CISA’s Known Exploited Vulnerabilities catalog since October 6, 2025.
CVE-2021-43226
Microsoft Windows Privilege Escalation Vulnerability
Added to KEV October 6, 2025
Alert details
- Source feed
- CISA KEV
- CVE ID
- CVE-2021-43226
- Affected products
- Windows · Microsoft Windows · Microsoft
What happened
Microsoft Windows Common Log File System Driver contains a privilege escalation vulnerability that could allow a local, privileged attacker to bypass certain security mechanisms.
What it means for your business
Microsoft Windows is listed in CISA's Known Exploited Vulnerabilities catalog (CVE-2021-43226). Microsoft Windows Common Log File System Driver contains a privilege escalation vulnerability that could allow a local, privileged attacker to bypass certain security mechanisms. CISA remediation due date: 2025-10-27. If you need help checking exposure, call (864) 335-9223.
Required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA due date: October 27, 2025
Sources
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