CVE-2025-62558 is a use-after-free vulnerability classified under CWE-416 affecting Microsoft SharePoint Enterprise Server 2016, specifically version 16.0.0. The flaw resides in the Microsoft Office Word component integrated with SharePoint, where improper memory management leads to a use-after-free condition. This vulnerability allows an attacker with local access to execute arbitrary code on the affected system by triggering the flaw through user interaction, such as opening a crafted Word document. The CVSS v3.1 score of 7.8 reflects a high severity, with attack vector being local (AV:L), low attack complexity (AC:L), no privileges required (PR:N), but user interaction required (UI:R). The impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H), meaning an attacker could fully compromise the system. The vulnerability was reserved in October 2025 and published in December 2025, with no known exploits in the wild at the time of publication. No official patch links are provided yet, indicating that mitigation may rely on workarounds until a patch is released. The vulnerability is critical for environments where SharePoint 2016 is used extensively, especially in enterprise settings where document collaboration is frequent. Attackers exploiting this flaw could gain code execution capabilities, potentially leading to lateral movement or data exfiltration within an organization.

For European organizations, the impact of CVE-2025-62558 can be severe due to the widespread use of Microsoft SharePoint Enterprise Server 2016 in enterprise environments for document management and collaboration. Successful exploitation could lead to unauthorized code execution on servers or client machines, resulting in data breaches, disruption of business operations, and potential compromise of sensitive information. Critical sectors such as finance, government, healthcare, and manufacturing that rely on SharePoint for document workflows are particularly vulnerable. The requirement for local access and user interaction somewhat limits remote exploitation but does not eliminate risk, especially in environments where users might open malicious documents or where insider threats exist. The high confidentiality, integrity, and availability impact means attackers could manipulate or destroy data, disrupt services, or establish persistent footholds. Given the lack of known exploits currently, proactive mitigation is essential to prevent future attacks. Additionally, the vulnerability could be leveraged in targeted attacks against European organizations with strategic importance, increasing geopolitical risk.

1. Monitor Microsoft security advisories closely and apply official patches for SharePoint Enterprise Server 2016 as soon as they become available. 2. Until patches are released, restrict local access to SharePoint servers and client machines to trusted personnel only. 3. Implement strict user education programs to warn about the risks of opening untrusted or unexpected Word documents, especially those received via email or external sources. 4. Use application whitelisting and endpoint protection solutions capable of detecting and blocking exploitation attempts related to use-after-free vulnerabilities. 5. Employ network segmentation to limit lateral movement if a system is compromised. 6. Regularly audit and monitor logs for suspicious activity indicative of exploitation attempts. 7. Consider upgrading to newer versions of SharePoint or Microsoft Office products that may have resolved this vulnerability. 8. Disable or limit macros and embedded content in Word documents where feasible to reduce attack surface. 9. Enforce the principle of least privilege on user accounts to minimize impact if exploitation occurs. 10. Conduct penetration testing and vulnerability assessments focused on SharePoint environments to identify and remediate related weaknesses.