CVE-2025-53736 is a medium-severity vulnerability classified under CWE-126 (Buffer Over-read) affecting Microsoft SharePoint Enterprise Server 2016, specifically version 16.0.0. The vulnerability arises from a buffer over-read condition in Microsoft Office Word components integrated with SharePoint. This flaw allows an unauthorized attacker to locally disclose sensitive information by reading beyond the intended buffer boundaries. The vulnerability does not require any privileges or user interaction, making it easier to exploit in local scenarios. The CVSS 3.1 base score is 6.8, reflecting a medium severity with the vector AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H, indicating local attack vector, low attack complexity, no privileges or user interaction required, unchanged scope, limited confidentiality impact, no integrity impact, but high availability impact. Although no known exploits are currently reported in the wild, the vulnerability could be leveraged by attackers with local access to the affected system to extract sensitive information from memory buffers, potentially leading to further attacks or data leakage. The lack of a patch link suggests that remediation may still be pending or in development. Given the integration of Microsoft Office Word with SharePoint, this vulnerability could be triggered when processing or rendering Word documents within SharePoint environments, exposing sensitive data stored or cached in memory buffers.

For European organizations, this vulnerability poses a risk primarily in environments where Microsoft SharePoint Enterprise Server 2016 is deployed, especially in sectors handling sensitive or confidential information such as government, finance, healthcare, and critical infrastructure. The local nature of the attack vector limits remote exploitation; however, insider threats or attackers who gain local access (e.g., via compromised credentials or physical access) could exploit this vulnerability to disclose sensitive information. The high availability impact suggests that exploitation could also disrupt SharePoint services, affecting business continuity. Given SharePoint's widespread use in European enterprises for document management and collaboration, exploitation could lead to unauthorized disclosure of intellectual property, personal data protected under GDPR, or other confidential organizational data. This could result in regulatory penalties, reputational damage, and operational disruptions.

Organizations should implement strict access controls to limit local access to SharePoint servers, including enforcing least privilege principles and robust authentication mechanisms. Monitoring and logging local access attempts can help detect suspicious activities. Since no patch is currently linked, organizations should stay alert for official Microsoft security updates addressing this vulnerability and apply them promptly once available. In the interim, consider isolating SharePoint servers from non-essential users and restricting document processing workflows to trusted personnel. Employ application whitelisting and endpoint protection solutions to prevent unauthorized code execution on SharePoint servers. Additionally, conduct regular security audits and vulnerability assessments focusing on SharePoint environments to identify and remediate potential exploitation paths. Backup critical data and have incident response plans ready to mitigate potential availability impacts.