Main Vulnerability Database Vulnerabilities #VU154779

Double free in Microsoft Windows and Windows Server - CVE-2026-83634

Published: October 14, 2026

Vulnerability identifier: #VU154779

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-83634

CWE-ID: CWE-415

Exploitation vector: Local access

Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to gain SYSTEM privileges.

The vulnerability exists due to double free in Windows BitLocker when operating locally. A local user can trigger the double-free condition to gain SYSTEM privileges.

Affected software

Microsoft Windows
Windows Server

How to mitigate CVE-2026-83634

Install security update from vendor's website.

Microsoft Windows - addressed in versions 11 23H2 10.0.22631.7652, 11 24H2 10.0.26100.9711, 11 25H2 10.0.26200.9711, 11 26H1 10.0.28000.3231
Windows Server - addressed in versions 2022 10.0.20348.5761, 2025 10.0.26100.33650

External References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-83634

Related Security Bulletins