CVE-2026-20876

Published: Jan 13, 2026Modified: Jan 15, 2026

6.7

Vector

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

Exploitability: 0.8 / Impact: 5.9

Source: secure@microsoft.com

Description

Heap-based buffer overflow in Windows Virtualization-Based Security (VBS) Enclave allows an authorized attacker to elevate privileges locally.

Affected (5)

Products: Microsoft: Windows 11 23h2, Windows 11 24h2, Windows 11 25h2, Windows Server 2022 23h2, Windows Server 2025

5 products

Windows 11 23h2

Windows 11 24h2

Windows 11 25h2

Windows Server 2022 23h2

Windows Server 2025

Configuration A

5 vulnerable

Vulnerable Software	Affected Versions
Microsoft Windows 11 23h2	Before 10.0.22631.6491
Microsoft Windows 11 24h2	Before 10.0.26100.7623
Microsoft Windows 11 25h2	Before 10.0.26200.7623
Microsoft Windows Server 2022 23h2	Before 10.0.25398.2092
Microsoft Windows Server 2025	Before 10.0.26100.32230

Related CWEs

Heap-based Buffer Overflow

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

References (1)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20876

Source: secure@microsoft.com

Vendor Advisory

Timeline

No history available yet.