CVE-2025-59237 is a deserialization vulnerability classified under CWE-502 affecting Microsoft SharePoint Enterprise Server 2016 (version 16.0.0). Deserialization vulnerabilities occur when untrusted data is processed by an application’s deserialization mechanism, potentially allowing attackers to manipulate serialized objects to execute arbitrary code. In this case, an authorized attacker with network access and privileges can send crafted serialized data to the SharePoint server, triggering remote code execution without requiring user interaction. The vulnerability impacts confidentiality, integrity, and availability, as attackers can execute arbitrary code, potentially leading to data theft, system compromise, or denial of service. The CVSS 3.1 score of 8.8 reflects the vulnerability’s high severity, with network attack vector, low attack complexity, and no user interaction required. Although no exploits are publicly known yet, the vulnerability’s characteristics suggest it could be weaponized quickly. SharePoint Enterprise Server 2016 is widely used in enterprise environments for collaboration and document management, making this vulnerability particularly critical. The lack of available patches at the time of publication increases the urgency for organizations to implement interim mitigations and monitor for suspicious activity. This vulnerability highlights the risks of deserialization flaws in complex enterprise software and the importance of secure coding and input validation practices.

For European organizations, exploitation of CVE-2025-59237 could lead to severe consequences including unauthorized remote code execution on critical SharePoint servers. This can result in data breaches involving sensitive corporate or personal data, disruption of collaboration services, and potential lateral movement within networks. Given SharePoint’s role in document management and internal communications, an attacker could manipulate or exfiltrate confidential information, impacting compliance with GDPR and other data protection regulations. The high severity and network-based exploitation increase the risk of widespread attacks, especially in sectors such as finance, government, healthcare, and manufacturing that rely heavily on SharePoint for daily operations. Additionally, the requirement for authorized access means insider threats or compromised credentials could facilitate exploitation. The absence of known public exploits currently provides a window for proactive defense, but the potential impact on confidentiality, integrity, and availability remains critical.

1. Apply official Microsoft patches immediately once released for SharePoint Enterprise Server 2016 to remediate the vulnerability. 2. Until patches are available, restrict privileged access to SharePoint servers and enforce the principle of least privilege to minimize the risk of authorized attacker exploitation. 3. Implement network segmentation and firewall rules to limit access to SharePoint management interfaces and services to trusted administrators only. 4. Monitor network traffic and logs for anomalous deserialization activity or unusual remote code execution indicators, using advanced threat detection tools. 5. Conduct regular credential audits and enforce strong authentication mechanisms, including multi-factor authentication, to reduce the risk of compromised accounts. 6. Review and harden SharePoint configurations to disable unnecessary features that may increase attack surface. 7. Educate administrators and security teams about the risks of deserialization vulnerabilities and the importance of timely patch management. 8. Consider deploying application-layer firewalls or runtime application self-protection (RASP) solutions capable of detecting and blocking malicious deserialization payloads.