CVE-2025-47176 is a high-severity remote code execution (RCE) vulnerability affecting Microsoft 365 Apps for Enterprise, specifically version 16.0.1. The vulnerability arises from improper handling of file path inputs in Microsoft Office Outlook, where the use of a path traversal sequence ('.../...//') allows an authorized attacker to execute arbitrary code locally. This is classified under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory), indicating that the application fails to properly sanitize or validate file paths, enabling attackers to access or execute files outside the intended directory. The CVSS v3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability, with low attack complexity and requiring low privileges but no user interaction. Although exploitation requires an authenticated user, the attacker can execute code with the privileges of the logged-in user, potentially leading to full system compromise. No known exploits are currently in the wild, and no patches have been published yet. The vulnerability was reserved on May 1, 2025, and published on June 10, 2025, indicating recent discovery and disclosure. The lack of user interaction requirement increases the risk, as attackers can leverage this flaw in automated or semi-automated attacks within compromised or insider environments. The vulnerability affects Microsoft 365 Apps for Enterprise, a widely used productivity suite in enterprise environments, making it a significant threat vector for organizations relying on Outlook for email and collaboration.

For European organizations, the impact of CVE-2025-47176 can be substantial. Microsoft 365 Apps for Enterprise is extensively deployed across Europe in both private and public sectors, including critical infrastructure, government agencies, financial institutions, and large enterprises. Successful exploitation could lead to unauthorized code execution on user machines, enabling attackers to steal sensitive data, deploy ransomware, or move laterally within networks. Given the high confidentiality, integrity, and availability impact, organizations could face data breaches, operational disruptions, and regulatory penalties under GDPR for failing to protect personal data. The requirement for an authenticated user limits remote exploitation but does not eliminate risk, as phishing or insider threats could provide the necessary access. The absence of user interaction requirement means that once authenticated, exploitation can be automated, increasing the threat to organizations with large user bases. Additionally, the vulnerability could be leveraged in targeted attacks against high-value European entities, potentially impacting national security or economic stability.

European organizations should implement a multi-layered mitigation strategy beyond generic patching advice. First, monitor and restrict the use of Microsoft 365 Apps for Enterprise version 16.0.1, prioritizing upgrades to patched versions as soon as Microsoft releases them. Until patches are available, apply application whitelisting and endpoint detection and response (EDR) solutions to detect and block suspicious process executions originating from Outlook or related processes. Enforce the principle of least privilege by limiting user permissions to reduce the impact of code execution. Implement strict network segmentation to contain potential lateral movement from compromised endpoints. Enhance email security by deploying advanced phishing detection and user awareness training to reduce the risk of credential compromise leading to authenticated access. Employ file integrity monitoring to detect unauthorized changes in critical directories. Additionally, review and harden Outlook configuration settings to restrict handling of suspicious file paths or attachments. Maintain vigilant logging and monitoring of authentication events and unusual process behaviors to enable rapid incident response.