CVE-2025-59229 is a vulnerability identified in Microsoft Office LTSC 2024 version 16.0.0, classified under CWE-248 (Uncaught Exception). This flaw arises when the application encounters an unexpected condition that is not properly handled, leading to an unhandled exception. Such an exception causes the application to crash, resulting in a denial of service (DoS) condition. The vulnerability can be exploited by an unauthorized attacker with local access to the system, requiring the user to interact with the vulnerable Office application to trigger the exception. The CVSS v3.1 base score is 5.5 (medium severity), reflecting that the attack vector is local (AV:L), the attack complexity is low (AC:L), no privileges are required (PR:N), but user interaction is necessary (UI:R). The impact is limited to availability (A:H) with no confidentiality or integrity loss. The scope remains unchanged (S:U). No known exploits are currently in the wild, and no official patches have been released yet. The vulnerability could be triggered by specially crafted input or document content that causes the Office application to fail to handle an exception properly. This leads to application crashes, potentially disrupting business workflows and productivity. Since the vulnerability is local and requires user interaction, remote exploitation is not feasible, limiting the attack surface. However, in environments where multiple users share workstations or where local access controls are weak, the risk increases. The vulnerability highlights the importance of robust exception handling in complex software like Microsoft Office to prevent service interruptions.

For European organizations, the primary impact of CVE-2025-59229 is the potential denial of service on workstations running Microsoft Office LTSC 2024. This can disrupt daily operations, especially in sectors heavily reliant on Office productivity tools such as finance, legal, and government agencies. Although the vulnerability does not compromise data confidentiality or integrity, the availability impact could lead to workflow interruptions, delayed document processing, and reduced employee productivity. Organizations with shared or less secure local access environments are more vulnerable to exploitation. Critical infrastructure sectors that depend on continuous availability of office applications for communication and documentation may experience operational setbacks. Additionally, the lack of a patch at the time of disclosure means organizations must rely on interim mitigations, increasing exposure duration. The medium severity rating suggests the threat is moderate but should not be ignored, particularly in environments with high compliance or operational continuity requirements.

1. Restrict local access to systems running Microsoft Office LTSC 2024 to trusted users only, minimizing the risk of unauthorized local exploitation. 2. Educate users to avoid opening suspicious or untrusted documents that could trigger the uncaught exception. 3. Monitor application logs and system stability for frequent or unusual Office crashes that may indicate exploitation attempts. 4. Implement application whitelisting and endpoint protection solutions that can detect abnormal application behavior or crashes. 5. Enforce least privilege principles to limit user permissions on workstations, reducing the impact of local attacks. 6. Prepare to deploy official patches or updates from Microsoft promptly once they become available. 7. Consider isolating critical systems or using virtualized environments to contain potential DoS effects. 8. Regularly back up important documents and workflows to mitigate productivity losses during outages. 9. Coordinate with IT and security teams to develop incident response plans addressing potential Office application crashes.