CVE-2025-58714 is a vulnerability categorized under CWE-284 (Improper Access Control) found in the Windows Ancillary Function Driver for WinSock component of Microsoft Windows 11 Version 25H2 (build 10.0.26200.0). This vulnerability allows an attacker with local authorized access to elevate their privileges on the affected system. The flaw arises because the access control mechanisms governing the Ancillary Function Driver for WinSock are insufficient, enabling privilege escalation without requiring user interaction. The CVSS v3.1 base score is 7.8, indicating high severity, with attack vector local (AV:L), low attack complexity (AC:L), privileges required (PR:L), no user interaction (UI:N), and impacts on confidentiality, integrity, and availability all rated high (C:H/I:H/A:H). The vulnerability was reserved on September 3, 2025, and published on October 14, 2025. No public exploits are known at this time, but the potential for exploitation exists given the low complexity and significant impact. The vulnerability could be leveraged by attackers who have gained limited local access to escalate privileges and gain full control over the system, potentially compromising sensitive data, system integrity, and availability. This is particularly concerning for enterprise environments where Windows 11 25H2 is deployed, as attackers could pivot from lower-privileged accounts to administrative control. The lack of patches at the time of disclosure necessitates immediate attention to access controls and monitoring until updates are released.

For European organizations, this vulnerability poses a significant risk as Windows 11 is widely adopted across corporate and government environments. Successful exploitation could allow attackers to escalate privileges from standard user accounts to administrative levels, enabling full system compromise. This threatens confidentiality by exposing sensitive data, integrity by allowing unauthorized changes, and availability by potentially disrupting critical services. Sectors such as finance, healthcare, government, and critical infrastructure are particularly vulnerable due to their reliance on Windows 11 and the sensitive nature of their data and operations. The local attack vector means that attackers need some form of local access, which could be achieved through phishing, insider threats, or exploiting other vulnerabilities to gain initial foothold. The high impact on all security properties combined with ease of exploitation elevates the threat level. European organizations must consider this vulnerability in their risk assessments and incident response planning, especially given the absence of known exploits but the high likelihood of future exploitation attempts.

1. Apply security patches from Microsoft immediately once they become available for Windows 11 Version 25H2 (build 10.0.26200.0). 2. Until patches are released, restrict local access to systems running the affected Windows version by enforcing strict physical and network access controls. 3. Implement least privilege principles rigorously, ensuring users operate with minimal necessary privileges to reduce the impact of potential local exploits. 4. Monitor event logs and system behavior for unusual privilege escalation attempts or suspicious activity related to the Ancillary Function Driver for WinSock. 5. Employ endpoint detection and response (EDR) solutions capable of detecting privilege escalation techniques. 6. Conduct regular security awareness training to reduce the risk of attackers gaining initial local access through social engineering or insider threats. 7. Use application whitelisting and device control policies to limit unauthorized software execution and device access. 8. Segment networks to limit lateral movement opportunities if local access is gained. 9. Maintain up-to-date backups and incident response plans to quickly recover from potential compromises. 10. Engage with Microsoft security advisories and threat intelligence feeds to stay informed about updates and exploit developments.