CVE-2025-29970 is a high-severity use-after-free vulnerability identified in the Microsoft Brokering File System component of Windows Server 2025, specifically affecting the Server Core installation version 10.0.26100.0. The vulnerability arises from improper handling of memory, where a resource is freed but later accessed, leading to undefined behavior. This flaw can be exploited by an authorized local attacker with limited privileges (PR:L) to elevate their privileges on the affected system. The vulnerability does not require user interaction (UI:N) and has a low attack complexity (AC:L), meaning exploitation is relatively straightforward once local access is obtained. The vulnerability impacts confidentiality, integrity, and availability (C:H/I:H/A:H), indicating that a successful exploit could allow the attacker to gain high-level access, manipulate or exfiltrate sensitive data, and disrupt system operations. The scope is unchanged (S:U), meaning the vulnerability affects only the vulnerable component without impacting other system components. Although no known exploits are currently in the wild, the presence of this vulnerability in a core server component makes it a significant risk, especially in environments where Windows Server 2025 Server Core installations are deployed. The lack of available patches at the time of publication increases the urgency for organizations to implement interim mitigations and monitor for updates from Microsoft.

For European organizations, the impact of CVE-2025-29970 could be substantial, particularly for enterprises and service providers relying on Windows Server 2025 Server Core installations for critical infrastructure, cloud services, or internal applications. Successful exploitation could lead to unauthorized privilege escalation, enabling attackers to execute arbitrary code with elevated rights, potentially leading to full system compromise. This can result in data breaches, disruption of business operations, and loss of trust. Given the high confidentiality, integrity, and availability impact, organizations handling sensitive personal data under GDPR or critical infrastructure sectors could face regulatory and operational consequences. The local attack vector implies that attackers need some form of initial access, which could be gained through other vulnerabilities, insider threats, or compromised credentials, making layered security controls essential. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, as attackers may develop exploits rapidly once details become public.

1. Immediate application of any official patches or updates from Microsoft once available is critical. 2. Until patches are released, restrict local access to Windows Server 2025 Server Core installations by enforcing strict access controls and monitoring for suspicious local activity. 3. Employ application whitelisting and endpoint detection and response (EDR) solutions to detect and prevent exploitation attempts. 4. Regularly audit user privileges and remove unnecessary administrative rights to minimize the pool of potential attackers who can exploit this vulnerability. 5. Implement network segmentation to limit lateral movement in case of compromise. 6. Monitor system logs and security alerts for unusual behavior indicative of privilege escalation attempts. 7. Educate system administrators about this vulnerability to ensure rapid response and adherence to security best practices. 8. Consider deploying additional host-based intrusion prevention systems (HIPS) that can detect use-after-free exploitation techniques.