CVE-2026-20941 is a vulnerability classified under CWE-59, which pertains to improper link resolution before file access, commonly known as 'link following'. This issue exists in the Host Process for Windows Tasks component of Microsoft Windows Server 2025, specifically in the Server Core installation variant. The vulnerability arises because the system improperly resolves symbolic links before accessing files, which can be exploited by an authorized local attacker to elevate their privileges. Essentially, an attacker with limited local permissions can create or manipulate symbolic links to trick the system into accessing or modifying files with higher privileges than intended. This can lead to unauthorized access, modification, or deletion of critical system files, thereby compromising confidentiality, integrity, and availability. The vulnerability requires local access and some level of privileges but does not require user interaction, making it more straightforward to exploit once local access is obtained. The CVSS v3.1 score of 7.8 indicates a high severity, with the vector showing low attack complexity, low privileges required, no user interaction, and high impact on confidentiality, integrity, and availability. The affected version is Windows Server 2025 (Server Core installation) build 10.0.26100.0. As of the published date, no known exploits have been reported in the wild, but the vulnerability is publicly disclosed and should be addressed promptly. No patches were listed at the time of this report, indicating that organizations should monitor for updates from Microsoft. The vulnerability is significant because Server Core installations are often used in critical infrastructure and data center environments where minimal attack surface and high security are expected.

For European organizations, the impact of CVE-2026-20941 can be substantial, especially for those relying on Windows Server 2025 Server Core installations in critical infrastructure, cloud services, or enterprise data centers. Successful exploitation allows local attackers to escalate privileges, potentially gaining administrative control over affected servers. This could lead to unauthorized access to sensitive data, disruption of services, or deployment of further malicious activities such as ransomware or lateral movement within networks. Given the high confidentiality, integrity, and availability impact, organizations could face operational downtime, data breaches, regulatory penalties under GDPR, and reputational damage. The requirement for local access somewhat limits remote exploitation but does not eliminate risk, as insider threats or attackers who gain initial footholds through other means could leverage this vulnerability to deepen their control. The absence of known exploits in the wild currently reduces immediate risk but does not preclude future exploitation. European sectors such as finance, healthcare, government, and critical infrastructure that use Windows Server 2025 Server Core are particularly vulnerable due to the critical nature of their services and data.

1. Monitor Microsoft security advisories closely and apply official patches or updates as soon as they become available for Windows Server 2025 Server Core installations. 2. Restrict local user privileges rigorously; ensure that only trusted administrators have elevated rights on servers. 3. Implement strict access controls and auditing on servers to detect and prevent unauthorized creation or manipulation of symbolic links. 4. Use application whitelisting and endpoint protection solutions capable of detecting suspicious file system activities related to symbolic links. 5. Employ network segmentation to limit lateral movement opportunities for attackers who gain local access. 6. Regularly review and harden server configurations, disabling unnecessary services and features to reduce attack surface. 7. Conduct internal security awareness and training to reduce insider threat risks. 8. Utilize host-based intrusion detection systems (HIDS) to monitor for anomalous behaviors indicative of privilege escalation attempts. 9. Consider deploying additional monitoring for file system changes and symbolic link creations on critical servers. 10. Prepare incident response plans that include scenarios involving local privilege escalation to ensure rapid containment and remediation.