CVE-2025-62199 is a use-after-free vulnerability identified in Microsoft Office 2016, specifically version 16.0.0. Use-after-free (CWE-416) vulnerabilities occur when a program continues to use memory after it has been freed, leading to undefined behavior including potential arbitrary code execution. In this case, the vulnerability allows an unauthorized attacker to execute code locally on the affected system. The CVSS 3.1 base score is 7.8, indicating high severity. The attack vector is local (AV:L), requiring low attack complexity (AC:L), no privileges (PR:N), but user interaction (UI:R). The scope is unchanged (S:U), and the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). This means an attacker can fully compromise the affected system if exploitation succeeds. The vulnerability was reserved on October 8, 2025, and published on November 11, 2025. No patches or exploits are currently known, but the lack of a patch means systems remain vulnerable. The vulnerability affects only Microsoft Office 2016 version 16.0.0, which is still widely used in many organizations. Exploitation likely involves convincing a user to open a malicious Office document, triggering the use-after-free condition and enabling code execution. This can lead to privilege escalation, data theft, or system disruption. The vulnerability is critical for environments relying on Office 2016 without updated mitigations or patches.

For European organizations, this vulnerability poses a significant risk due to the widespread use of Microsoft Office 2016 in enterprise environments. Successful exploitation can lead to full system compromise, allowing attackers to steal sensitive data, disrupt operations, or move laterally within networks. Confidentiality, integrity, and availability of critical business information and systems are at risk. Sectors such as finance, government, healthcare, and critical infrastructure are particularly vulnerable due to the sensitive nature of their data and regulatory requirements. The local attack vector means attackers need to convince users to open malicious documents, which is feasible through phishing campaigns. The absence of known exploits in the wild provides a window for proactive defense, but the lack of patches increases risk. European organizations with legacy systems or delayed patch management are especially exposed. The impact extends to potential regulatory penalties under GDPR if personal data is compromised.

1. Restrict or disable the use of Microsoft Office 2016 version 16.0.0 where possible, encouraging upgrades to supported versions with security patches. 2. Implement strict application whitelisting and control policies to prevent execution of unauthorized code, especially from Office documents. 3. Employ advanced email filtering and phishing detection to reduce the likelihood of malicious document delivery. 4. Educate users about the risks of opening unsolicited or suspicious Office documents, emphasizing the need for caution. 5. Monitor endpoint behavior for signs of exploitation attempts, such as unusual process spawning or memory access patterns. 6. Use endpoint detection and response (EDR) tools to detect and block exploitation techniques related to use-after-free vulnerabilities. 7. Isolate legacy systems that must run Office 2016 to limit potential lateral movement. 8. Regularly review and update incident response plans to include scenarios involving local code execution vulnerabilities. 9. Engage with Microsoft support for any forthcoming patches or workarounds and apply them promptly once available.