Buffer over-read in Microsoft Windows and Windows Server - CVE-2026-105506

Vulnerability identifier: #VU164641

CSH Severity: Medium

CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-105506

CWE-ID: CWE-126

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to disclose potentially sensitive information from heap memory.

The vulnerability exists due to a buffer over-read in Windows Shell when accessing memory beyond a buffer boundary. A local user can trigger the over-read through local exploitation requiring user interaction to potentially read small portions of heap memory.

Microsoft Windows
Windows Server

Install security update from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7846, 10 22H2 10.0.19045.7846, 10 1607 10.0.14393.9688, 10 1809 10.0.17763.9487, 11 23H2 10.0.22631.7711, 11 24H2 10.0.26100.9911, 11 24H2 10.0.26100.9974, 11 25H2 10.0.26200.9911, 11 25H2 10.0.26200.9974, 11 26H1 10.0.28000.3501
Windows Server - addressed in versions 2016 10.0.14393.9688, 2019 10.0.17763.9487, 2022 10.0.20348.5870, 2025 10.0.26100.33730, 2025 10.0.26100.33822

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-105506