CVE-2025-58735 is a use-after-free vulnerability classified under CWE-416 affecting Microsoft Windows 11 Version 25H2 (build 10.0.26200.0). The flaw resides in Inbox COM Objects, which are components used for interprocess communication and object management within Windows. A use-after-free occurs when a program continues to use a pointer after the memory it points to has been freed, leading to memory corruption. In this case, an unauthorized attacker with local access can exploit the vulnerability by triggering the use of a freed COM object, resulting in arbitrary code execution with the privileges of the current user. The CVSS v3.1 score is 7.0 (high), reflecting that the attack vector is local (AV:L), requires high attack complexity (AC:H), no privileges (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). No known exploits have been reported in the wild yet, and no patches have been linked at the time of publication. The vulnerability was reserved on September 3, 2025, and published on October 14, 2025. This vulnerability could be leveraged by attackers to execute arbitrary code locally, potentially leading to privilege escalation or system compromise if combined with other vulnerabilities or misconfigurations.

For European organizations, this vulnerability poses a significant risk especially in environments where Windows 11 Version 25H2 is deployed. The ability for an unauthorized local attacker to execute arbitrary code can lead to data breaches, disruption of services, and compromise of critical systems. Organizations handling sensitive personal data, financial information, or critical infrastructure operations could face severe confidentiality, integrity, and availability impacts. Since exploitation requires local access and user interaction, insider threats or social engineering attacks could facilitate exploitation. The high impact on all security properties means that successful exploitation could allow attackers to install malware, steal data, or disrupt operations. The lack of known exploits currently provides a window for proactive mitigation, but the presence of this vulnerability in a widely used OS version means that many enterprises and government agencies across Europe could be targeted once exploits become available.

1. Monitor Microsoft security advisories closely and apply official patches immediately once released to remediate the vulnerability. 2. Restrict local access to Windows 11 25H2 systems by enforcing strict access controls and limiting user privileges to the minimum necessary. 3. Implement application whitelisting and endpoint protection solutions that can detect anomalous behavior indicative of exploitation attempts. 4. Educate users about the risks of social engineering and the importance of cautious interaction with unexpected prompts or files, as user interaction is required for exploitation. 5. Use network segmentation to isolate critical systems running Windows 11 25H2 to reduce the risk of lateral movement by attackers with local access. 6. Employ regular memory integrity and system integrity checks to detect potential exploitation attempts or system compromises. 7. Maintain up-to-date backups and incident response plans to quickly recover from potential attacks leveraging this vulnerability.