CVE-2025-50154 is a vulnerability classified under CWE-200 (Exposure of Sensitive Information) affecting Microsoft Windows 10 Version 1809, specifically the Windows File Explorer component. The vulnerability allows an unauthorized attacker to gain access to sensitive information by exploiting a flaw in how File Explorer handles certain network operations, leading to potential spoofing attacks over a network. The attack vector is network-based (AV:N), requiring no privileges (PR:N) but does require user interaction (UI:R), such as opening or browsing files or network shares in File Explorer. The scope of the vulnerability is unchanged (S:U), meaning the impact is limited to the vulnerable component without affecting other system components. The confidentiality impact is high (C:H), indicating that sensitive data can be exposed, but integrity (I:N) and availability (A:N) remain unaffected. The CVSS score of 6.5 reflects a medium severity level. No patches or known exploits are currently available, but the vulnerability poses a risk of information leakage that could facilitate further attacks, such as phishing or man-in-the-middle spoofing. The vulnerability was reserved in June 2025 and published in August 2025, indicating recent discovery. The lack of patches necessitates immediate mitigation strategies to protect affected systems.

For European organizations, the exposure of sensitive information through this vulnerability could lead to unauthorized disclosure of confidential data, potentially including internal file names, network paths, or user information. This could facilitate targeted phishing campaigns, social engineering, or further network-based attacks. Organizations in sectors such as finance, healthcare, government, and critical infrastructure are particularly at risk due to the sensitivity of their data and regulatory requirements under GDPR. The vulnerability does not allow direct system compromise or denial of service but undermines confidentiality, which can have cascading effects on trust and compliance. Since Windows 10 Version 1809 is an older release, organizations that have not upgraded may be disproportionately affected, especially those with legacy systems or extended support contracts. The absence of known exploits reduces immediate risk but also means attackers could develop exploits without detection. The network-based nature of the attack increases risk in environments with extensive file sharing or remote access.

1. Prioritize upgrading affected systems from Windows 10 Version 1809 to a supported and patched Windows version to eliminate the vulnerability. 2. Restrict network access to file shares and limit exposure of File Explorer network browsing to trusted networks only, using network segmentation and firewall rules. 3. Disable or restrict features in File Explorer that interact with untrusted network resources, such as network discovery or automatic network share browsing. 4. Educate users to avoid interacting with unknown or suspicious network locations and to report unexpected prompts or behaviors in File Explorer. 5. Implement strict access controls and monitoring on network shares to detect unusual access patterns that might indicate exploitation attempts. 6. Use endpoint detection and response (EDR) tools to monitor for anomalous network activity related to File Explorer. 7. Regularly audit and update security policies to ensure legacy systems are identified and remediated promptly. 8. Apply network-level protections such as intrusion detection/prevention systems (IDS/IPS) tuned to detect spoofing or reconnaissance activities.