CVE-2025-29978 is a high-severity use-after-free vulnerability identified in Microsoft Office PowerPoint, part of the Microsoft 365 Apps for Enterprise suite, specifically affecting version 16.0.1. The vulnerability arises from improper handling of memory in PowerPoint, where an object is freed but later accessed, leading to undefined behavior. This flaw can be exploited by an unauthorized attacker to execute arbitrary code locally on the victim's machine. The attack vector requires local access (AV:L), low attack complexity (AC:L), no privileges required (PR:N), but does require user interaction (UI:R), such as opening a malicious PowerPoint file. The vulnerability impacts confidentiality, integrity, and availability (all rated high), indicating that successful exploitation could lead to full system compromise. The scope is unchanged (S:U), meaning the impact is limited to the vulnerable component. Although no known exploits are currently reported in the wild, the vulnerability is publicly disclosed and rated with a CVSS 3.1 score of 7.8, reflecting its seriousness. The vulnerability is categorized under CWE-416 (Use After Free), a common memory corruption issue that can lead to arbitrary code execution. No official patches or mitigations have been linked yet, but given the critical nature and Microsoft’s typical response, a security update is expected. Organizations using Microsoft 365 Apps for Enterprise, especially PowerPoint, should be aware of this vulnerability and prepare to apply patches once available.

For European organizations, the impact of CVE-2025-29978 could be significant due to the widespread use of Microsoft 365 Apps for Enterprise across various sectors including government, finance, healthcare, and critical infrastructure. Successful exploitation could allow attackers to execute arbitrary code locally, potentially leading to data breaches, ransomware deployment, or lateral movement within networks. Confidentiality breaches could expose sensitive personal and corporate data, violating GDPR and other privacy regulations. Integrity and availability impacts could disrupt business operations, causing financial losses and reputational damage. The requirement for user interaction (e.g., opening a malicious PowerPoint file) means phishing campaigns or malicious document distribution remain likely attack vectors. The absence of known exploits in the wild currently reduces immediate risk, but the public disclosure increases the likelihood of exploit development. European organizations with remote or hybrid workforces may be particularly vulnerable if users open untrusted documents on enterprise devices.

1. Immediate mitigation should include heightened user awareness and training to avoid opening unsolicited or suspicious PowerPoint files, especially from unknown sources. 2. Implement strict email filtering and attachment scanning to detect and block potentially malicious documents. 3. Employ application control policies to restrict execution of unauthorized code and sandbox document processing where possible. 4. Monitor endpoint behavior for anomalies indicative of exploitation attempts, such as unusual PowerPoint process activity or memory corruption indicators. 5. Prepare for rapid deployment of Microsoft security updates by maintaining an up-to-date patch management process and testing environment. 6. Use endpoint detection and response (EDR) tools to detect and respond to exploitation attempts quickly. 7. Consider disabling or restricting macros and embedded content in PowerPoint files if not required. 8. Network segmentation and least privilege principles can limit the impact of a compromised host. These steps go beyond generic advice by focusing on document handling policies, user training, and proactive monitoring tailored to this vulnerability’s characteristics.