CVE-2025-53740 is a use-after-free vulnerability classified under CWE-416 found in Microsoft Office 2019, specifically version 19.0.0. Use-after-free vulnerabilities occur when a program continues to use memory after it has been freed, leading to undefined behavior that attackers can exploit to execute arbitrary code. In this case, the vulnerability allows an unauthorized attacker to execute code locally without requiring privileges or user interaction, which is unusual and increases the risk profile. The CVSS 3.1 base score is 8.4 (high), with the vector indicating local attack vector (AV:L), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). The exploitability is rated as official (E:U), with an official remediation level (RL:O) and confirmed report confidence (RC:C). Although no exploits are currently known in the wild, the vulnerability's characteristics suggest that once exploited, it could allow attackers to gain full control over the affected system, compromising sensitive data and disrupting operations. The lack of patch links indicates that a fix may not yet be publicly available, emphasizing the need for vigilance and interim mitigations.

For European organizations, this vulnerability poses a significant threat due to the widespread use of Microsoft Office 2019 across enterprises, government agencies, and critical infrastructure sectors. Successful exploitation could lead to unauthorized code execution, resulting in data breaches, system compromise, and potential disruption of business operations. The high impact on confidentiality, integrity, and availability means sensitive information could be stolen or altered, and systems could be rendered inoperable. Given that no privileges or user interaction are required, attackers with local access—such as through compromised insider accounts or lateral movement within networks—could leverage this vulnerability to escalate privileges or establish persistent footholds. This risk is particularly acute for sectors handling sensitive personal data under GDPR, financial institutions, and public sector entities. The absence of known exploits currently provides a window for proactive defense, but the vulnerability's severity demands immediate attention.

Since no official patches are currently available, European organizations should implement layered defensive measures. First, restrict local access to systems running Microsoft Office 2019 by enforcing strict access controls and monitoring for unusual local activity. Employ application whitelisting and endpoint detection and response (EDR) solutions capable of detecting anomalous memory usage patterns indicative of use-after-free exploitation. Enable and enforce Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR) to hinder exploitation attempts. Conduct thorough audits of user privileges and remove unnecessary local accounts to reduce attack surface. Prepare for rapid deployment of patches once Microsoft releases them by maintaining an up-to-date inventory of affected systems. Additionally, educate staff about the risks of local compromise and implement network segmentation to limit lateral movement. Regularly back up critical data and test restoration procedures to mitigate potential availability impacts.