CVE-2025-58734 is a use-after-free vulnerability classified under CWE-416 affecting Inbox COM Objects in Microsoft Windows 11 Version 25H2 (build 10.0.26200.0). Use-after-free vulnerabilities occur when a program continues to use a pointer after the memory it points to has been freed, leading to undefined behavior including potential arbitrary code execution. In this case, the vulnerability allows an unauthorized attacker to execute code locally by exploiting improper memory management within the Inbox COM Objects, which are components used for messaging and communication services in Windows. The vulnerability requires local access and user interaction, making remote exploitation infeasible without prior access. The CVSS v3.1 score is 7.0, indicating high severity, with vector metrics AV:L (local attack vector), AC:H (high attack complexity), PR:N (no privileges required), UI:R (user interaction required), and full impact on confidentiality, integrity, and availability (C:H/I:H/A:H). No known exploits have been reported in the wild, and no official patches have been released at the time of publication. The vulnerability was reserved on September 3, 2025, and published on October 14, 2025. Exploitation could allow attackers to execute arbitrary code with the privileges of the logged-in user, potentially leading to system compromise or data breaches. The vulnerability affects a widely deployed operating system version, increasing the risk surface for organizations.

For European organizations, the impact of CVE-2025-58734 is significant due to the widespread use of Windows 11 in enterprise environments. Successful exploitation can lead to full system compromise, allowing attackers to access sensitive data, disrupt operations, or deploy further malware. Critical sectors such as finance, healthcare, government, and industrial control systems could face severe operational and reputational damage. Since the vulnerability requires local access and user interaction, insider threats or social engineering attacks could be vectors. The lack of a patch increases exposure time, and organizations relying on Windows 11 Version 25H2 without mitigations are vulnerable. The potential for privilege escalation and code execution elevates the risk of lateral movement within networks, impacting confidentiality, integrity, and availability of critical systems.

Until an official patch is released, organizations should implement the following mitigations: 1) Enforce the principle of least privilege by restricting user permissions to prevent unauthorized local code execution. 2) Limit access to systems running Windows 11 Version 25H2 to trusted personnel only. 3) Employ application whitelisting and endpoint protection solutions to detect and block suspicious activities related to COM object exploitation. 4) Educate users to recognize and avoid social engineering attempts that could trigger the vulnerability. 5) Monitor system logs and behavior for anomalies indicative of exploitation attempts, such as unexpected COM object usage or crashes. 6) Segment networks to contain potential compromises and prevent lateral movement. 7) Prepare for rapid deployment of patches once available by maintaining up-to-date asset inventories and patch management processes. 8) Consider temporary use of alternative systems or versions if critical operations depend on vulnerable endpoints.