CVE-2025-49756 is a vulnerability identified in Microsoft 365 Apps for Enterprise, specifically version 16.0.1. The issue stems from the use of a broken or risky cryptographic algorithm within the Office Developer Platform. This cryptographic weakness allows an authorized attacker—meaning someone with at least limited access privileges—to bypass a security feature locally on the affected system. The vulnerability is classified under CWE-327, which relates to the use of cryptographic algorithms that are considered insecure or deprecated, potentially undermining the confidentiality and integrity of protected data or operations. The CVSS v3.1 base score is 3.3, indicating a low severity level. The attack vector is local (AV:L), requiring low privileges (PR:L) and user interaction (UI:R), with high attack complexity (AC:H). The impact on confidentiality and integrity is low, and there is no impact on availability. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability does not appear to allow remote exploitation or elevate privileges beyond the existing authorized user context, but it could weaken security controls that rely on the compromised cryptographic algorithm, potentially facilitating further attacks or data exposure if combined with other vulnerabilities or insider threats.

For European organizations, the impact of CVE-2025-49756 is relatively limited due to its low severity and local attack vector. However, organizations relying heavily on Microsoft 365 Apps for Enterprise for sensitive document handling, development, or internal automation could face risks if attackers with authorized access exploit this cryptographic weakness to bypass security features. This could lead to unauthorized data access or manipulation within the local environment, undermining data integrity and confidentiality. In regulated sectors such as finance, healthcare, or government, even low-severity cryptographic weaknesses can have compliance implications under GDPR and other data protection frameworks. Additionally, the presence of this vulnerability may increase the attack surface for insider threats or malware that gains local access, potentially facilitating lateral movement or privilege escalation chains. The lack of remote exploitation reduces the risk of widespread attacks but does not eliminate targeted local threats, especially in environments with shared workstations or insufficient endpoint security controls.

To mitigate this vulnerability effectively, European organizations should: 1) Monitor for and apply any forthcoming patches or updates from Microsoft promptly once available, as no patch links are currently provided. 2) Restrict local access to systems running Microsoft 365 Apps for Enterprise to trusted and authorized personnel only, enforcing strict endpoint access controls and user privilege management. 3) Employ application whitelisting and endpoint detection and response (EDR) solutions to detect anomalous behaviors that might indicate exploitation attempts. 4) Review and harden cryptographic policies and configurations within the Office Developer Platform if configurable, replacing deprecated algorithms with modern, secure alternatives. 5) Conduct regular security awareness training emphasizing the risks of local attacks and the importance of safeguarding credentials and access. 6) Implement robust logging and monitoring to detect suspicious local activity that could indicate attempts to bypass security features. 7) Consider network segmentation and least privilege principles to limit the impact of any local compromise. These steps go beyond generic advice by focusing on the local nature of the threat and the cryptographic context.