CVE-2025-62559 is a use-after-free vulnerability classified under CWE-416 affecting Microsoft SharePoint Enterprise Server 2016, specifically version 16.0.0. The vulnerability arises from improper memory management in the Microsoft Office Word component integrated with SharePoint, where an object is freed but later accessed, leading to undefined behavior. This flaw can be exploited by an attacker who crafts a malicious Word document and convinces a user to open or interact with it, triggering local code execution without requiring prior authentication or elevated privileges. The CVSS 3.1 score of 7.8 reflects high severity due to its impact on confidentiality, integrity, and availability, combined with low attack complexity and no required privileges, though user interaction is necessary. The vulnerability is currently published with no known exploits in the wild and no patches released yet, increasing the urgency for monitoring and mitigation. The flaw could allow attackers to execute arbitrary code in the context of the logged-in user, potentially leading to privilege escalation, data theft, or system compromise within enterprise environments relying on SharePoint for document management and collaboration.

For European organizations, this vulnerability poses a significant risk due to the widespread use of Microsoft SharePoint Enterprise Server 2016 in corporate, governmental, and critical infrastructure sectors. Exploitation could lead to unauthorized code execution on affected systems, resulting in data breaches, disruption of document workflows, and potential lateral movement within networks. Confidentiality is at risk as attackers could access sensitive documents; integrity could be compromised by altering or injecting malicious content; availability could be affected if systems are destabilized or taken offline. Given the integration of SharePoint with other Microsoft services, the impact could cascade, affecting broader IT environments. The requirement for user interaction means phishing or social engineering campaigns could be leveraged to trigger the exploit, increasing the threat surface. The absence of known exploits currently provides a window for proactive defense, but the high severity demands immediate attention to prevent future attacks.

1. Monitor Microsoft security advisories closely and apply official patches immediately upon release to remediate the vulnerability. 2. Implement strict email and document filtering to block or quarantine suspicious Word documents, especially those originating from untrusted sources. 3. Educate users about the risks of opening unsolicited or unexpected documents and train them to recognize phishing attempts. 4. Employ application whitelisting and endpoint protection solutions capable of detecting anomalous behavior related to memory corruption exploits. 5. Restrict or disable macros and embedded content in Office documents where possible to reduce attack vectors. 6. Use network segmentation to limit the spread of potential compromises originating from SharePoint servers. 7. Regularly audit and monitor SharePoint logs and user activities for unusual access patterns or errors indicative of exploitation attempts. 8. Consider upgrading to supported SharePoint versions with improved security features if feasible, as SharePoint 2016 may have limited ongoing support.