CVE-2025-47994 is a high-severity vulnerability identified in Microsoft Office 2019 (version 19.0.0) involving the deserialization of untrusted data, classified under CWE-502. Deserialization vulnerabilities occur when an application processes serialized data from untrusted sources without proper validation, allowing attackers to manipulate the data to execute arbitrary code or escalate privileges. In this case, the flaw allows an unauthorized local attacker to elevate privileges on the affected system. The CVSS 3.1 base score of 7.8 reflects a high impact, with the vector indicating local attack vector (AV:L), low attack complexity (AC:L), no privileges required (PR:N), but requiring user interaction (UI:R). The scope is unchanged (S:U), and the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk due to the potential for privilege escalation, which could lead to full system compromise if exploited. The lack of available patches at the time of publication increases the urgency for mitigation. This vulnerability specifically affects Microsoft Office 2019, a widely used productivity suite in enterprise and government environments, making it a critical concern for organizations relying on this software for daily operations.

For European organizations, the impact of CVE-2025-47994 could be substantial. Microsoft Office 2019 is extensively deployed across various sectors including finance, healthcare, government, and manufacturing, all of which handle sensitive data. Successful exploitation could allow attackers to gain elevated privileges on user machines, potentially enabling lateral movement within networks, data exfiltration, or deployment of further malware. This could disrupt business continuity, compromise confidential information protected under GDPR, and damage organizational reputation. Since the attack requires local access and user interaction, insider threats or social engineering attacks could be vectors. The high impact on confidentiality, integrity, and availability means that critical systems and data could be at risk, especially in environments where endpoint security controls are insufficient or outdated. The absence of known exploits currently provides a window for proactive defense, but also indicates the need for immediate attention to prevent future exploitation.

Given the absence of an official patch at the time of reporting, European organizations should implement layered mitigation strategies. First, enforce strict endpoint security policies including application whitelisting to restrict execution of unauthorized code. Employ robust user training to reduce the risk of social engineering attacks that could trigger the vulnerability. Limit local user privileges to the minimum necessary to reduce the impact of privilege escalation attempts. Use advanced endpoint detection and response (EDR) solutions to monitor for suspicious deserialization activities or unusual privilege escalations. Network segmentation can help contain potential lateral movement if a device is compromised. Regularly update and audit Microsoft Office installations and related components to ensure timely application of patches once released. Additionally, consider disabling or restricting features in Office that handle serialized data if feasible in the operational context. Finally, maintain comprehensive backups and incident response plans tailored to address potential exploitation scenarios involving privilege escalation.