CVE-2026-20932 is an information disclosure vulnerability classified under CWE-200, affecting Microsoft Windows 10 Version 1809, specifically build 10.0.17763.0. The vulnerability resides in Windows File Explorer, where an authorized attacker with local access and limited privileges can disclose sensitive information without requiring user interaction. The attack vector is local (AV:L), with low attack complexity (AC:L), requiring privileges (PR:L) but no user interaction (UI:N). The vulnerability does not affect system integrity or availability but has a high impact on confidentiality (C:H). The scope remains unchanged (S:U), meaning the vulnerability affects only the vulnerable component and does not propagate to other components. The CVSS v3.1 base score is 5.5, indicating a medium severity level. No known exploits are currently in the wild, and no official patches have been linked yet, though the vulnerability has been publicly disclosed. The flaw could allow attackers to access sensitive files or data that should otherwise be protected, potentially leading to information leakage that could facilitate further attacks or violate data privacy regulations. The vulnerability is significant for environments where Windows 10 Version 1809 is still operational, especially in sectors handling sensitive or regulated data.

For European organizations, the primary impact of CVE-2026-20932 is the unauthorized disclosure of sensitive information, which can compromise confidentiality and potentially violate data protection regulations such as GDPR. This could lead to reputational damage, regulatory fines, and loss of customer trust. Since the vulnerability requires local access and privileges, the risk is heightened in environments where multiple users share systems or where endpoint security is lax. Attackers gaining access to confidential files could leverage this information for further attacks, including social engineering or privilege escalation. Critical infrastructure, government agencies, and enterprises handling sensitive personal or financial data are particularly at risk. The lack of known exploits reduces immediate threat levels but does not eliminate the risk, especially if attackers develop exploits. Organizations relying on Windows 10 Version 1809, which remains in use in some sectors due to legacy application compatibility, are vulnerable until mitigations or patches are applied.

Organizations should first identify and inventory all systems running Windows 10 Version 1809 (build 10.0.17763.0) to assess exposure. Since no official patches are currently linked, apply the following mitigations: restrict local access to sensitive systems by enforcing strict access controls and user privilege management; implement robust endpoint security solutions that monitor and alert on unusual file access patterns; employ application whitelisting to limit unauthorized software execution; enforce network segmentation to reduce lateral movement opportunities; educate users on the risks of local privilege misuse; and consider upgrading affected systems to a supported Windows version with security updates. Additionally, enable auditing and logging of file access events to detect potential exploitation attempts. Regularly review and update security policies to minimize the risk of insider threats or unauthorized local access.