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 memory after it has been freed, leading to undefined behavior such as arbitrary code execution. In this case, the flaw allows an unauthorized attacker with local access to execute code by triggering the vulnerable COM object to access freed memory. The vulnerability does not require elevated privileges but does require user interaction, increasing attack complexity. The CVSS 3.1 vector (AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H) indicates local attack vector, high complexity, no privileges required, user interaction required, unchanged scope, and high impact on confidentiality, integrity, and availability. Although no public exploits are known yet, the potential for local privilege escalation and system compromise is significant. The vulnerability was reserved in early September 2025 and published in mid-October 2025, with no patches currently available, indicating a zero-day window. The affected component, Inbox COM Objects, is part of Windows system components responsible for inter-process communication and automation, making exploitation impactful. This vulnerability poses a serious risk to systems running this Windows version, especially in environments where local access cannot be tightly controlled.

For European organizations, this vulnerability presents a critical risk due to the widespread adoption of Windows 11, particularly in enterprise environments. Successful exploitation can lead to arbitrary code execution with the privileges of the logged-in user, potentially allowing attackers to install malware, steal sensitive data, or disrupt operations. The high impact on confidentiality, integrity, and availability means that critical systems could be compromised, leading to data breaches, operational downtime, and reputational damage. Sectors such as finance, healthcare, government, and critical infrastructure are especially vulnerable given their reliance on Windows 11 and the sensitivity of their data. The requirement for local access and user interaction somewhat limits remote exploitation but does not eliminate risk, as insider threats or social engineering attacks could facilitate exploitation. The absence of known exploits currently provides a window for proactive defense, but organizations must act swiftly to mitigate risk before exploit code becomes publicly available.

1. Monitor Microsoft security advisories closely and apply patches immediately once released to address CVE-2025-58738. 2. Restrict local access to Windows 11 systems, enforcing strict physical and logical access controls to minimize unauthorized local user presence. 3. Employ application whitelisting and endpoint detection and response (EDR) solutions capable of detecting anomalous behavior related to COM object exploitation. 4. Educate users about the risks of social engineering and the importance of not executing untrusted code or clicking suspicious prompts, as user interaction is required for exploitation. 5. Implement least privilege principles to limit user permissions, reducing the impact of potential code execution. 6. Use virtualization or sandboxing for high-risk applications to contain potential exploitation attempts. 7. Regularly audit and harden system configurations, disabling unnecessary COM components if feasible. 8. Maintain comprehensive logging and monitoring to detect early signs of exploitation attempts or unusual local activity.