CVE-2025-62554 is a vulnerability classified under CWE-843 (Access of Resource Using Incompatible Type, or 'type confusion') affecting Microsoft Office LTSC 2024 version 16.0.0. This vulnerability allows an attacker to execute arbitrary code locally by exploiting the way Microsoft Office handles certain resource types internally. Type confusion occurs when a program accesses a resource or object as if it were a different type than it actually is, leading to undefined behavior, memory corruption, or execution of malicious code. The vulnerability requires no privileges and no user interaction, indicating that an attacker with local access can exploit it directly. The CVSS v3.1 base score is 8.4 (high), reflecting high impact on confidentiality, integrity, and availability, with low attack complexity and no required privileges or user interaction. Although no public exploits have been reported yet, the vulnerability's nature suggests it could be used for local privilege escalation or to establish persistence on compromised systems. Microsoft Office LTSC 2024 is a long-term servicing channel product, often used in enterprise environments for stability and extended support, making this vulnerability particularly relevant for organizations relying on this version. The lack of available patches at the time of publication necessitates immediate risk mitigation through access control and monitoring until official fixes are released.

The vulnerability poses a significant risk to European organizations using Microsoft Office LTSC 2024, as it allows unauthorized local code execution without requiring user interaction or privileges. This could lead to full system compromise, including data theft, manipulation, or destruction, and disruption of business operations. Given Microsoft Office's widespread use in Europe across government, finance, healthcare, and critical infrastructure sectors, exploitation could result in severe confidentiality breaches and operational outages. Attackers with local access—such as malicious insiders or those who gain initial footholds through other means—could leverage this vulnerability to escalate privileges and move laterally within networks. The absence of known exploits currently reduces immediate risk but also underscores the importance of proactive mitigation. The vulnerability's impact on availability could disrupt essential services, while integrity and confidentiality impacts could lead to data breaches and compliance violations under regulations like GDPR.

1. Restrict local access to systems running Microsoft Office LTSC 2024 to trusted personnel only, employing strict access controls and monitoring. 2. Implement application whitelisting and endpoint detection and response (EDR) solutions to detect anomalous behavior indicative of exploitation attempts. 3. Disable or limit unnecessary local accounts and services that could be leveraged to gain local access. 4. Monitor system logs and security events for unusual activity related to Microsoft Office processes or memory corruption indicators. 5. Prepare for rapid deployment of official Microsoft patches once released by establishing a tested patch management process specifically for LTSC versions. 6. Educate IT and security teams about the vulnerability details and encourage vigilance for potential exploitation signs. 7. Consider network segmentation to limit lateral movement if local compromise occurs. 8. Use least privilege principles for user accounts to reduce the impact of potential exploitation.