CVE-2025-53730 is a high-severity use-after-free vulnerability identified in Microsoft Office 2019, specifically affecting the Visio component. A use-after-free (CWE-416) vulnerability occurs when a program continues to use a pointer after the memory it points to has been freed, potentially leading to arbitrary code execution, memory corruption, or crashes. In this case, the vulnerability allows an unauthorized attacker to execute code locally on the affected system. The CVSS v3.1 base score is 7.8, indicating a high impact. The vector details specify that the attack requires local access (AV:L), low attack complexity (AC:L), no privileges required (PR:N), but user interaction is necessary (UI:R). The scope is unchanged (S:U), and the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). The exploitability is rated as unproven (E:U), and the remediation level is official (RL:O) with a confirmed report confidence (RC:C). No known exploits are currently in the wild, and no patches have been linked yet. This vulnerability could be triggered by a maliciously crafted Visio file or interaction within the Office environment, leading to local code execution, which could be leveraged to escalate privileges or deploy malware on the affected system.

For European organizations, this vulnerability poses a significant risk, especially for enterprises and government agencies relying on Microsoft Office 2019 with Visio for diagramming and documentation tasks. Successful exploitation could lead to local code execution, potentially allowing attackers to install malware, steal sensitive data, or disrupt operations. Since the attack requires local access and user interaction, the threat is more pronounced in environments where users might open untrusted Visio files, such as through phishing campaigns or insider threats. The high impact on confidentiality, integrity, and availability means that critical business processes could be compromised, leading to data breaches, operational downtime, and reputational damage. Organizations with strict data protection regulations, such as those under GDPR, could face compliance issues if this vulnerability is exploited to exfiltrate personal or sensitive data.

European organizations should implement a multi-layered mitigation strategy: 1) Restrict the use of Microsoft Office Visio 2019 to trusted users and environments, minimizing exposure to untrusted files. 2) Educate users about the risks of opening unsolicited or suspicious Visio files, emphasizing phishing awareness. 3) Employ application whitelisting and endpoint protection solutions capable of detecting anomalous behavior related to use-after-free exploits. 4) Monitor local system activity for unusual processes or code execution attempts originating from Office applications. 5) Since no official patch is currently linked, organizations should apply any forthcoming security updates from Microsoft promptly. 6) Consider deploying sandboxing or virtualization for opening Visio files in high-risk environments to contain potential exploitation. 7) Implement strict access controls and least privilege principles to limit the impact of local code execution if exploited.