CVE-2026-20944 is an out-of-bounds read vulnerability classified under CWE-125, found in Microsoft Office Word component of Microsoft 365 Apps for Enterprise version 16.0.1. This vulnerability allows an attacker to read memory outside the intended buffer boundaries, which can lead to arbitrary code execution on the local machine. The flaw does not require any privileges or user interaction, making it particularly dangerous. The vulnerability affects confidentiality, integrity, and availability by enabling unauthorized code execution, potentially allowing attackers to run malicious payloads, escalate privileges, or disrupt system operations. The CVSS v3.1 base score is 8.4, reflecting its high severity with local attack vector, low attack complexity, no privileges required, and no user interaction needed. Although no public exploits have been reported yet, the vulnerability's characteristics suggest it could be weaponized quickly. Microsoft has not yet published patches or mitigations, so organizations must monitor for updates and prepare to deploy them promptly. The vulnerability's presence in a widely used enterprise productivity suite increases its potential impact across diverse sectors.

For European organizations, this vulnerability poses a significant risk due to the widespread use of Microsoft 365 Apps for Enterprise across government, finance, healthcare, and critical infrastructure sectors. Exploitation could lead to local system compromise, data breaches, and disruption of business operations. Confidential information could be exposed or altered, and attackers could establish persistence or move laterally within networks. The lack of required privileges or user interaction lowers the barrier for exploitation, increasing the threat surface. Organizations with remote or hybrid work environments relying on Microsoft Office are particularly vulnerable. The potential impact includes loss of sensitive data, operational downtime, reputational damage, and regulatory penalties under GDPR if personal data is compromised.

1. Monitor Microsoft security advisories closely for the release of official patches addressing CVE-2026-20944 and apply them immediately upon availability. 2. Until patches are available, implement application whitelisting and restrict execution of untrusted code on endpoints running Microsoft 365 Apps. 3. Employ endpoint detection and response (EDR) solutions to monitor for unusual behavior indicative of exploitation attempts. 4. Limit local user permissions to the minimum necessary to reduce the impact of local code execution. 5. Use network segmentation to isolate critical systems and reduce lateral movement opportunities. 6. Educate users about the risks of opening untrusted documents, even though user interaction is not required for this exploit, as a general security best practice. 7. Regularly audit and update software inventories to ensure vulnerable versions are identified and remediated promptly. 8. Consider deploying application sandboxing or virtualization technologies to contain potential exploitation.