Out-of-bounds read in Microsoft Windows and Windows Server - CVE-2026-105549

Vulnerability identifier: #VU164672

CSH Severity: Low

CVSS v4: 5.1 [CVSS:4.0/AV:P/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-105549

CWE-ID: CWE-125

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a user with physical access to system to disclose information from heap memory.

The vulnerability exists due to an out-of-bounds read in Windows Smart Card when handling smart card operations. A user with physical access to system can exploit the memory access error through a physical attack 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-2026-105549
• https://support.microsoft.com/help/5131291

• Multiple vulnerabilities in Microsoft Windows