CVE-2026-20820

Windows Common Log File System Driver Elevation of Privilege Vulnerability

Heap-based buffer overflow in Windows Common Log File System Driver allows an authorized attacker to elevate privileges locally.

Affected

Microsoft · Windows 10 Version 1607 · Windows 10 Version 1809 · Windows 10 Version 21H2 · Windows 10 Version 22H2 · Windows 11 version 23H2 · Windows 11 Version 23H2

CVSS v3.1 MICROSOFT

7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

2.56% chance of exploitation in the next 30 days, 85th percentile

Published

2026-01-13

Updated

2026-07-30

Proof-of-concept exploits (1)

• uname1able/CVE-2026-208200★ · 2026-03-18

Security advisories

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20820

References

• CVE Record
• NVD entry

Related

• CVE-2022-24481
• CVE-2022-24521
• CVE-2022-37969
• CVE-2025-21333
• CVE-2025-29824
• CVE-2026-24291