CVE-2026-108450 in 365 Apps for Enterprise
Summary
by MITRE • 10/16/2026
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 10/17/2026
The vulnerability described constitutes a critical security flaw within the Microsoft Office Word application, specifically manifesting as a heap-based buffer overflow condition. 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 embedded objects that contain malformed data structures. The attacker exploits this weakness to overwrite adjacent memory locations with malicious code or shellcode, thereby gaining control over the execution flow of the application process. This mechanism allows for arbitrary code execution on the target system under the context of the currently logged-in user, which often implies elevated privileges depending on the default security settings and user account configurations.
From a technical perspective, heap-based buffer overflows are particularly dangerous because they can be exploited remotely without requiring physical access to the machine or direct interaction with the operating system's kernel. The attack vector is primarily network-based, meaning an attacker could potentially exploit this vulnerability by sending a malicious document via email or hosting it on a website that the victim visits using Word-compatible viewing tools. When the user opens the compromised file, the application attempts to parse the data structures within it. Due to insufficient bounds checking during memory allocation and copy operations, the overflow occurs, corrupting heap metadata or function pointers. This corruption enables the attacker to redirect program execution to their injected payload, leading to full system compromise.
The operational impact of this vulnerability is severe, as it facilitates remote code execution with minimal user interaction beyond opening a file. Once executed, the malicious code can perform a wide range of destructive actions including installing malware, stealing sensitive data such as credentials and documents, creating backdoors for persistent access, or using the compromised machine as part of a botnet. The ability to execute code over the network significantly increases the attack surface, allowing threat actors to target organizations at scale through phishing campaigns or drive-by downloads that leverage this specific flaw in Word processing logic.
To mitigate the risks associated with this vulnerability, immediate patching is essential. Organizations should ensure that all instances of Microsoft Office are updated to the latest version containing the security fixes provided by Microsoft for this specific CVE. Additionally, implementing application control policies can restrict the execution of untrusted scripts and binaries, thereby limiting the impact if an exploit succeeds. Network segmentation and strict email filtering rules that inspect attachments for known malicious patterns or anomalies in file structures also serve as effective defensive measures. Users should be educated to exercise caution when opening documents from unknown sources and to enable Protected View features which isolate potentially unsafe content in a sandboxed environment before allowing full access. Regular vulnerability assessments and penetration testing can further help identify any residual exposure to this class of heap-based memory corruption issues across the enterprise infrastructure.