CVE-2026-108447 in Office
Summary
by MITRE • 10/16/2026
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 10/16/2026
The vulnerability described constitutes a critical security flaw within the Microsoft Office Word application, specifically manifesting as a heap-based buffer overflow. This type of memory corruption error occurs when a program writes data beyond the allocated boundaries of a buffer located in the heap segment of computer memory. In the context of Microsoft Office Word, this defect is typically triggered by processing specially crafted documents or files that contain malformed data structures. When an attacker constructs a malicious file designed to exploit this specific weakness, they can manipulate the internal state of the application during parsing operations. The overflow allows for arbitrary write access to adjacent memory regions, which provides the necessary conditions for overwriting critical control data such as function pointers or exception handlers. This manipulation effectively redirects the execution flow of the program away from its intended path and toward code injected by the attacker.
The operational impact of this vulnerability is severe due to its potential for remote code execution with network-based attack vectors. Because Microsoft Office Word is a ubiquitous productivity tool, users frequently open documents received via email or downloaded from untrusted sources without rigorous verification. An unauthorized attacker can leverage this flaw to execute arbitrary commands on the victim's system with the same privileges as the current user. This capability allows for comprehensive compromise of the affected machine, including the installation of malware, theft of sensitive data, creation of new accounts for persistent access, or modification of system configurations. The network aspect implies that no physical interaction is required; a single click to open an email attachment can initiate the exploit chain, making this a high-risk vector for widespread automated attacks and targeted phishing campaigns.
From a technical classification perspective, this vulnerability aligns with Common Weakness Enumeration identifier CWE-120, which denotes Buffer Copy without Checking Size of Input Classic Heap Overflow. This categorization highlights the fundamental failure in input validation where the application does not adequately verify that incoming data fits within the pre-allocated memory space. Furthermore, the exploitation technique maps to MITRE ATT&CK framework techniques related to Command and Scripting Interpreter execution or potentially Process Injection depending on the specific payload delivery mechanism employed by the attacker. The heap-based nature of the overflow distinguishes it from stack overflows, often requiring more sophisticated exploitation methods such as heap spraying or use-after-free primitives to achieve reliable code execution across different versions of Windows and Office software.
Mitigation strategies must address both immediate remediation and long-term defensive posture improvements. Organizations should immediately apply vendor-provided security patches that correct the memory management logic within Word's document parsing engine. Until patches are deployed, users should be instructed to avoid opening documents from unknown or untrusted sources and to enable Protected View for all incoming attachments. Network-level defenses such as intrusion detection systems can be configured to detect anomalous traffic patterns associated with exploit attempts targeting Office applications. Additionally, implementing application whitelisting policies can prevent the execution of unauthorized scripts or binaries that might be dropped by an active exploit. Regular security awareness training is also essential to reduce the likelihood of users inadvertently triggering these vulnerabilities through social engineering tactics.