CVE-2026-64907 in Office
Summary
by MITRE • 08/11/2026
Stack-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code locally.
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Analysis
by VulDB Data Team • 08/13/2026
A stack-based buffer overflow vulnerability exists in Microsoft Office Word that enables unauthorized attackers to execute arbitrary code locally on affected systems. This vulnerability stems from insufficient input validation within the word processing application's memory management routines, specifically when handling malformed or oversized data structures during document processing operations. The flaw occurs when the application attempts to write data beyond the boundaries of a pre-allocated stack buffer, creating potential for memory corruption that can be exploited by malicious actors. The vulnerability is categorized under CWE-121 Stack-based Buffer Overflow, which represents one of the most prevalent and dangerous types of buffer overflow conditions in software applications.
The technical implementation of this exploit typically involves crafting a specially formatted document containing oversized data sequences that trigger the buffer overflow condition when processed by Word. When the vulnerable application parses such malicious content, it overwrites adjacent memory locations including return addresses and function pointers on the stack. This memory corruption allows attackers to redirect program execution flow to malicious code payloads that are carefully positioned within the corrupted memory space. The attack vector requires user interaction through opening a malicious document, making social engineering techniques particularly effective in exploiting this vulnerability.
The operational impact of this vulnerability is severe as it provides local privilege escalation capabilities and enables persistent code execution within the context of the Word application process. Attackers can leverage this vulnerability to gain unauthorized access to systems, establish backdoors, and potentially escalate privileges to system-level access depending on the user's permissions. The exploitability of this condition is enhanced by modern exploitation techniques such as return-oriented programming and data injection methods that can bypass standard security mechanisms like stack canaries and address space layout randomization. This vulnerability affects multiple versions of Microsoft Office Word across different operating systems including windows 7 through windows 10.
Mitigation strategies for this vulnerability include immediate application of microsoft security patches and updates to address the buffer overflow condition in affected word versions. System administrators should implement application whitelisting controls to restrict execution of unauthorized code and employ runtime protection mechanisms such as exploit prevention software. Network segmentation and user access controls can help limit potential lateral movement if exploitation occurs, while regular security monitoring and endpoint detection capabilities can identify suspicious activities associated with exploitation attempts. Organizations should also consider implementing zero-trust security models that validate all application execution regardless of origin or user permissions, aligning with defensive strategies outlined in the mitre attack framework under techniques related to privilege escalation and code injection.
The vulnerability demonstrates critical weaknesses in software memory management practices and highlights the importance of rigorous input validation and secure coding standards. Industry best practices recommend implementing bounds checking mechanisms, using safe string handling functions, and conducting regular security code reviews to prevent such conditions from persisting in software applications. The presence of this vulnerability underscores the necessity for continuous security assessments and timely patch management processes to protect against known exploits that target common software weaknesses documented in security databases maintained by organizations like mitre corporation and nist.