MSRC-CVE-2026-62775 — Windows Container Isolation FS Filter Driver (unionfs.sys) Information Disclosure Vulnerability

Summary

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

Details

What type of information could be disclosed by this vulnerability?
The type of information that could be disclosed if an attacker successfully exploited this vulnerability includes unauthorized access to the file system, specifically file path information.

Security updates
10.0.28000.2704 — https://support.microsoft.com/help/5121000

Vulnerabilities 1

Medium 5.5

CVE-2026-62775

Windows Container Isolation FS Filter Driver (unionfs.sys) Information Disclosure Vulnerability

Incorrect authorization in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to disclose information locally.

Microsoft Windows 11 version 26H1 Windows

Aug 11, 2026

Revision history

2026-08-11 #1
Information published.

References

CVE-2026-62775 Windows Container Isolation FS Filter Driver (unionfs.sys) Information Disclosure Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62775
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