High 7.8Known exploited (CISA KEV)Published Sep 15, 2021

CVE-2021-36955Windows Common Log File System Driver Elevation of Privilege Vulnerability

Updated under an hour ago (Oct 27, 2026, 7:20 PM ET)

Does this affect you?

It affects Microsoft Windows 10 Version 1507 and 24 other products. Add what you run to find out whether that includes you.

CISA lists it as known exploited since Nov 3, 2021; federal agencies had to remediate by Nov 17, 2021, and it is known to be used in ransomware. Treat that date as your deadline.

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Every CVE for Microsoft Windows 10 Version 1507

Exploited in the last 30 days

Windows Common Log File System Driver Elevation of Privilege Vulnerability

CVSS: 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
Weakness (CWE): Not given
Known exploited: Added to CISA KEV Nov 3, 2021; federal remediation due Nov 17, 2021; known ransomware useApply updates per vendor instructions.
EPSS (exploitation in the next 30 days): 4.07% (percentile 91)
Assigned by: microsoft
NVD analysis: Analyzed
Record last updated: Aug 10, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Microsoft Windows 10 Version 1507 microsoft:windows_10_1507	from 10.0.10240.0 before 10.0.10240.19060	CNA record
Microsoft Windows 10 Version 1607 microsoft:windows_10_1607	from 10.0.14393.0 before 10.0.14393.4651	CNA record
Microsoft Windows 10 Version 1809 microsoft:windows_10_1809	from 10.0.17763.0 before 10.0.17763.2183	CNA record
Microsoft Windows 10 Version 1909 microsoft:windows_10_1909	from 10.0.0 before 10.0.18363.1801	CNA record
Microsoft Windows 10 Version 2004 microsoft:windows_10_2004	from 10.0.0 before 10.0.19041.1237	CNA record
Microsoft Windows 10 Version 20H2 microsoft:windows_10_20h2	from 10.0.0 before 10.0.19042.1237	CNA record
Microsoft Windows 10 Version 21H1 microsoft:windows_10_21h1	from 10.0.0 before 10.0.19043.1237	CNA record
Microsoft Windows 7 microsoft:windows_7 (from the name)	from 6.1.0 before 6.1.7601.25712	CNA record
Microsoft Windows 7 Service Pack 1 microsoft:windows_7_service_pack_1 (from the name)	from 6.1.0 before 6.1.7601.25712	CNA record
Microsoft Windows 8.1 microsoft:windows_8.1 (from the name)	from 6.3.0 before 6.3.9600.20120	CNA record
1–10 of 38

References

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36955	vendor-advisory, patch
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36955	patch, vendor-advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36955	us-government-resource

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.