HIGH

CVE-2026-20820

CVSS v3

7.8

HIGH

EPSS Score

2.6 %

exploit probability, as of 2026-09-25

CISA KEV

known exploited

Exploitation

—

SSVC status

Description

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

Technical details

CVSS v3 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Published: 2026-01-13
Last Modified: 2026-07-30

Frequently asked questions

What is CVE-2026-20820?

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

Is CVE-2026-20820 actively exploited?

Active exploitation of CVE-2026-20820 has not been confirmed. Its EPSS score was 2.6% on 2026-09-25, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-20820?

CVE-2026-20820 has a CVSS v3 base score of 7.8 (HIGH severity), with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C.

Is CVE-2026-20820 affecting your environment?

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