MSRC-CVE-2026-20819 — Windows Virtualization-Based Security (VBS) Information Disclosure Vulnerability

Summary

Impact: Information Disclosure. Microsoft rating: Important. Not known to be exploited — Exploitation Less Likely. Customer action: Required.

Details

What type of information could be disclosed by this vulnerability?
An attacker who successfully exploited this vulnerability could view Virtual Trust Level 1 (VTL1) data from Virtual Trust 0 (VTL0) which is the least privileged level.

Security updates
10.0.26200.7623 — https://support.microsoft.com/help/5074109
10.0.22631.6491 — https://support.microsoft.com/help/5073455

Vulnerabilities 1

Medium 5.5

CVE-2026-20819

Windows Virtualization-Based Security (VBS) Information Disclosure Vulnerability

Untrusted pointer dereference in Windows Virtualization-Based Security (VBS) Enclave allows an authorized attacker to disclose information locally.

Microsoft Windows 11 Version 24H2 Windows 11 version 23H2 Windows 11 Version 25H2 Windows

Jan 13, 2026

Revision history

2026-01-13 #1
Information published.

References

CVE-2026-20819 Windows Virtualization-Based Security (VBS) Information Disclosure Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20819
Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
Common Vulnerability Scoring System
https://www.first.org/cvss