CVE-2025-62564 is an out-of-bounds read vulnerability categorized under CWE-125 affecting Microsoft Excel within Microsoft 365 Apps for Enterprise version 16.0.1. The vulnerability arises due to improper bounds checking during memory operations, allowing an attacker to read memory outside the intended buffer. This memory corruption can be leveraged to execute arbitrary code locally on the victim's machine. The attack vector involves a specially crafted Excel file that, when opened, triggers the vulnerability. No prior privileges are required, but user interaction is necessary to open the malicious file. The vulnerability impacts confidentiality, integrity, and availability by enabling unauthorized code execution, potentially leading to data theft, system manipulation, or denial of service. The CVSS 3.1 score of 7.8 (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) indicates a high-severity issue with local attack vector, low attack complexity, no privileges required, but user interaction needed. No patches or known exploits are currently reported, but the vulnerability's nature makes it a critical concern for enterprise environments relying on Microsoft 365 Apps. The vulnerability was reserved in October 2025 and published in December 2025, indicating recent discovery and disclosure.

The impact of CVE-2025-62564 is significant for organizations worldwide using Microsoft 365 Apps for Enterprise, especially version 16.0.1. Successful exploitation can lead to local code execution, allowing attackers to gain control over affected systems, steal sensitive data, alter or destroy information, and disrupt business operations. Since Microsoft Excel is widely used in enterprise environments, the vulnerability poses a risk of targeted attacks via malicious Excel documents, potentially delivered through phishing or insider threats. The requirement for user interaction means social engineering remains a key exploitation vector. The high confidentiality, integrity, and availability impact could lead to severe operational disruptions, data breaches, and compliance violations. Organizations in sectors with high reliance on Microsoft Office productivity tools, such as finance, government, healthcare, and critical infrastructure, face elevated risks. The absence of known exploits currently provides a window for proactive mitigation before widespread exploitation occurs.

To mitigate CVE-2025-62564, organizations should: 1) Monitor Microsoft security advisories closely and apply official patches immediately upon release for Microsoft 365 Apps for Enterprise version 16.0.1. 2) Implement strict email and file filtering policies to block or quarantine suspicious Excel files, especially from untrusted sources. 3) Educate users on the risks of opening unsolicited or unexpected Excel attachments and encourage verification of file origins. 4) Employ application control and sandboxing techniques to restrict Excel's ability to execute arbitrary code or access sensitive system resources. 5) Use endpoint detection and response (EDR) solutions to monitor for anomalous behaviors indicative of exploitation attempts. 6) Consider disabling macros and other potentially risky Excel features unless explicitly required and secured. 7) Maintain regular backups and incident response plans to recover quickly from potential compromises. These targeted measures go beyond generic advice by focusing on controlling the attack vector and limiting the impact of exploitation.