CVE-2026-108436 in Office
Summary
by MITRE • 10/16/2026
Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information 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 document parsing engine of Microsoft Office Word, specifically manifesting as an out-of-bounds read condition. This type of memory corruption error occurs when the application attempts to access data stored in computer memory beyond the boundaries of allocated buffers or arrays. In the context of Microsoft Office applications, this typically arises during the processing of complex document structures, such as those containing embedded objects, specific formatting instructions, or malformed XML elements within a Word file. When an attacker crafts a malicious document designed to trigger this parsing logic error, they can cause the application to read memory locations that were not intended for access by the current process context. This behavior is classified under Common Weakness Enumeration (CWE) as CWE-125 Out-of-bounds Read, which represents a fundamental failure in input validation and boundary checking within software development practices.
The operational impact of this vulnerability centers on unauthorized information disclosure rather than immediate code execution or system compromise. By exploiting the out-of-bounds read condition, an attacker can potentially extract sensitive data residing in adjacent memory spaces that belong to other processes or contain internal application states. This disclosed information may include cryptographic keys, authentication tokens, personal identifiable information stored temporarily in memory, or proprietary document content from previously opened files. The attack vector is primarily network-based if the malicious Word file is delivered via email attachments, shared drives, or web downloads, allowing for remote exploitation without requiring physical access to the target machine. This aligns with MITRE ATT&CK techniques related to Data from Local System Retrieval and potentially Credential Access depending on what specific memory contents are exposed during the exploit execution.
Mitigation strategies must address both immediate remediation and long-term defensive posture improvements. The primary defense is the timely application of security patches released by Microsoft that correct the buffer boundary checks within the Word parsing engine. Organizations should prioritize deploying these updates across all endpoints running affected versions of Office software. Additionally, implementing strict email filtering policies to block or quarantine suspicious attachments can reduce the attack surface. Users must be educated on social engineering tactics often used to deliver such malicious documents and advised against opening files from untrusted sources. From a technical standpoint, enabling Protected View for documents downloaded from the internet forces them into a sandboxed environment where potentially dangerous content is not executed until explicitly trusted by the user. Furthermore, deploying endpoint detection and response solutions that monitor for anomalous memory access patterns can help identify exploitation attempts in real time before significant data exfiltration occurs.