CVE-2025-29800 is a vulnerability classified under CWE-269 (Improper Privilege Management) found in Microsoft AutoUpdate (MAU) for Mac, specifically version 4.0.0. MAU is responsible for updating Microsoft Office and related software on macOS systems. The vulnerability allows an authorized local attacker—meaning someone with existing access to the system but with limited privileges—to escalate their privileges to a higher level, potentially root or administrative rights. This escalation occurs due to improper handling of privilege boundaries within the update mechanism, which may allow the attacker to execute code or commands with elevated privileges without requiring user interaction. The CVSS 3.1 base score is 7.8 (high), reflecting the local attack vector (AV:L), low attack complexity (AC:L), required privileges (PR:L), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). No public exploits have been reported yet, but the vulnerability is publicly disclosed and should be considered a significant risk. The lack of a patch link indicates that a fix may still be pending or in progress. Since MAU is widely used in enterprise Mac environments to maintain Microsoft software, exploitation could lead to full system compromise, data theft, or disruption of services.

For European organizations, this vulnerability could lead to severe consequences including unauthorized access to sensitive corporate data, disruption of business operations, and potential lateral movement within networks if attackers gain elevated privileges on Mac endpoints. Organizations relying on Microsoft Office on Mac devices, especially in sectors like finance, healthcare, and government, face increased risk of data breaches or ransomware attacks. The ability to escalate privileges locally means that insider threats or attackers who have gained limited access through other means could fully compromise affected systems. This could undermine confidentiality, integrity, and availability of critical information systems, leading to regulatory non-compliance and reputational damage. The impact is heightened in environments where endpoint security controls are weak or where Mac devices are used to access critical infrastructure or sensitive data.

Immediate mitigation steps include restricting local user permissions to the minimum necessary, implementing strict endpoint security policies, and monitoring for unusual privilege escalation activities on Mac devices. Organizations should prepare to deploy patches from Microsoft as soon as they become available and prioritize updating all affected MAU installations. Employing application whitelisting and endpoint detection and response (EDR) tools can help detect and prevent exploitation attempts. Additionally, enforcing multi-factor authentication and network segmentation can limit the potential damage from compromised endpoints. Security teams should also conduct audits of local user accounts and privilege assignments to reduce the attack surface. Since no patch is currently linked, organizations should stay alert to vendor advisories and consider temporary workarounds such as disabling automatic updates or restricting MAU execution until a fix is released.