CVE-2025-58738 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 such as arbitrary code execution. In this case, the vulnerability allows an unauthorized attacker with local access to execute arbitrary code by exploiting the improper handling of COM objects within the Windows inbox components. The attack complexity is high, requiring user interaction, but no privileges or prior authentication are necessary, making it accessible to local attackers who can trick users into triggering the flaw. The CVSS 3.1 base score is 7.0, indicating a high severity with impacts on confidentiality, integrity, and availability. The vulnerability was reserved on September 3, 2025, and published on October 14, 2025. No public exploits have been reported yet, but the potential for local privilege escalation or system compromise exists if exploited. The lack of available patches at the time of publication means organizations must rely on interim mitigations. The vulnerability affects a widely deployed operating system version, increasing its potential impact. The Inbox COM Objects are integral to Windows functionality, so exploitation could disrupt normal operations or allow persistent malware installation.

For European organizations, the impact of CVE-2025-58738 could be significant, especially in sectors relying heavily on Windows 11 25H2, such as finance, healthcare, government, and critical infrastructure. Successful exploitation could lead to local privilege escalation, enabling attackers to gain control over affected systems, exfiltrate sensitive data, or disrupt services. The vulnerability’s ability to compromise confidentiality, integrity, and availability means that data breaches, ransomware deployment, or system outages are plausible outcomes. Organizations with large numbers of Windows 11 endpoints are particularly vulnerable, as the attack requires local access and user interaction, which could be facilitated through phishing or insider threats. The absence of known exploits currently reduces immediate risk but also means defenders must be proactive. The high attack complexity somewhat limits mass exploitation but targeted attacks against high-value European entities remain a concern. The vulnerability could also be leveraged as a stepping stone in multi-stage attacks, increasing overall threat severity.

1. Monitor Microsoft’s security advisories closely and apply official patches immediately upon release to remediate the vulnerability. 2. Until patches are available, implement strict local access controls to limit the ability of unauthorized users to interact with vulnerable systems. 3. Employ application whitelisting and endpoint protection solutions capable of detecting anomalous COM object usage or suspicious local code execution attempts. 4. Educate users on the risks of social engineering and phishing that could trigger user interaction required for exploitation. 5. Use Windows security features such as Controlled Folder Access and exploit protection settings to reduce attack surface. 6. Regularly audit and restrict administrative privileges to minimize the impact of local attacks. 7. Deploy network segmentation to isolate critical systems and limit lateral movement in case of compromise. 8. Implement comprehensive logging and monitoring to detect early signs of exploitation attempts involving COM objects or unusual process behavior.