CVE-2025-53718 is a use-after-free vulnerability classified under CWE-416, found in the Windows Ancillary Function Driver for WinSock on Windows 10 Version 1507 (build 10.0.10240.0). This vulnerability arises when the driver improperly manages memory, freeing an object while it is still in use, which can lead to arbitrary code execution or privilege escalation. An attacker with authorized local access and low privileges can exploit this flaw to elevate their privileges to higher levels, potentially SYSTEM level, without requiring user interaction. The attack complexity is high, meaning exploitation requires specific conditions and expertise. The vulnerability affects confidentiality, integrity, and availability by allowing attackers to gain unauthorized control over the system. Although no known exploits are currently in the wild and no patches have been released, the vulnerability poses a significant risk to systems still running this legacy Windows 10 version. The CVSS v3.1 score is 7.0, reflecting a high severity with local attack vector, high attack complexity, and required privileges. The scope is unchanged, meaning the vulnerability affects only the vulnerable component without impacting other components directly. The vulnerability was reserved in July 2025 and published in August 2025, indicating recent discovery. The lack of patches necessitates immediate mitigation through system upgrades and privilege management.

For European organizations, this vulnerability poses a serious risk especially to those still operating legacy Windows 10 Version 1507 systems, which may be present in industrial control systems, government agencies, or enterprises with slow upgrade cycles. Successful exploitation allows attackers to escalate privileges locally, potentially leading to full system compromise, data breaches, or disruption of critical services. The impact on confidentiality includes unauthorized access to sensitive data; on integrity, unauthorized modification of system files or configurations; and on availability, potential system crashes or denial of service. Given the high attack complexity and local access requirement, remote exploitation is unlikely, but insider threats or compromised local accounts could leverage this vulnerability. The absence of patches increases the window of exposure, making timely mitigation critical. Organizations in sectors with stringent regulatory requirements (e.g., GDPR) face compliance risks if this vulnerability is exploited.

1. Upgrade affected systems to a supported and patched version of Windows 10 or later to eliminate the vulnerability. 2. Restrict local user privileges strictly, ensuring users operate with the least privilege necessary to reduce the risk of privilege escalation. 3. Implement application whitelisting and endpoint detection and response (EDR) solutions to monitor and block suspicious local activities. 4. Harden network segmentation to limit access to critical systems only to authorized personnel. 5. Conduct regular audits of local accounts and remove or disable unnecessary accounts to reduce attack surface. 6. Employ strict patch management policies to ensure timely updates once patches become available. 7. Educate users about the risks of local privilege escalation and enforce strong access controls. 8. Monitor system logs for unusual activity indicative of exploitation attempts. 9. Consider deploying virtual desktop infrastructure (VDI) or sandbox environments to isolate critical workloads from local user environments.