CVE-2025-62571: 
vulnerability analysis and mitigation

CVE-2025-62571 is an improper input validation vulnerability in Windows Installer that allows an authorized local attacker to elevate privileges. Disclosed on December 9, 2025, as part of Microsoft's December 2025 Patch Tuesday, it affects a broad range of Windows versions including Windows 10 (1607, 1809, 21H2, 22H2), Windows 11 (23H2, 24H2, 25H2), Windows Server 2008 through Windows Server 2025. It carries a CVSS v3.1 base score of 7.8 (High) (Microsoft MSRC).

The vulnerability is classified under CWE-20 (Improper Input Validation) and resides in the Windows Installer component. An attacker with low-privileged local access can supply maliciously crafted input that bypasses validation logic within the installer service, triggering a privilege escalation to administrative or SYSTEM-level control. No user interaction is required, and the attack complexity is low, making it straightforward to exploit once local access is obtained (Microsoft MSRC, Feedly).

Successful exploitation grants an attacker high-level administrative control over the affected system, with full impact to confidentiality, integrity, and availability. A low-privileged local user could escalate to SYSTEM privileges, enabling installation of malware, access to sensitive data, modification of system configurations, or use of the compromised host as a pivot point for lateral movement within the network (Microsoft MSRC).

Microsoft released patches for CVE-2025-62571 as part of the December 2025 Cumulative Update. Affected versions should be updated to the following builds or later: Windows 10 21H2/22H2 → 10.0.19044.6691 / 10.0.19045.6691; Windows 11 23H2 → 10.0.22631.6345; Windows 11 24H2/25H2 → 10.0.26100.7392 / 10.0.26200.7392; Windows Server 2016 → 10.0.14393.8688; Windows Server 2019 → 10.0.17763.8146; Windows Server 2022 → 10.0.20348.4467; Windows Server 2022 23H2 → 10.0.25398.2025; Windows Server 2025 → 10.0.26100.7392. As interim mitigations, organizations should restrict local user privileges, enforce least-privilege access controls, and monitor for suspicious privilege escalation activity using endpoint protection tools (Microsoft MSRC).

The vulnerability was covered as part of broader December 2025 Patch Tuesday roundups by multiple security outlets. Bleeping Computer noted the December 2025 update addressed 57 flaws including 3 zero-days, with CVE-2025-62571 among the elevation-of-privilege issues patched (Bleeping Computer). Zero Day Initiative and Sophos also published Patch Tuesday reviews covering the December release (ZDI Blog, Sophos News). No specific researcher commentary or social media discussion focused exclusively on this CVE was identified.