CVE-2026-80080 in Office
Summary
by MITRE • 09/09/2026
Double free in Microsoft Office Word allows an unauthorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability described involves a critical memory management error within the Microsoft Office Word application, specifically classified as a double-free condition. This type of flaw occurs when a program attempts to deallocate or release a block of memory that has already been freed by a previous operation. In the context of complex software like word processing applications, which handle intricate document structures and various file formats, such errors can arise from improper state management during the parsing of maliciously crafted files. When an attacker provides a specially constructed Word document to a victim, the application may process specific elements in a way that triggers this double-free sequence. The immediate technical consequence is often memory corruption, where internal data structures become inconsistent or overwritten with arbitrary values due to the undefined behavior resulting from freeing already released resources.
From a security perspective, this vulnerability falls under the category of CWE-415, which defines Double Free as a weakness that can lead to various forms of exploitation. The primary risk associated with double-free vulnerabilities is their potential to facilitate remote code execution. By carefully crafting the input data and potentially leveraging heap spraying techniques or other memory corruption primitives, an attacker can manipulate the program's control flow. This manipulation allows for the injection and subsequent execution of arbitrary machine code within the context of the vulnerable application. Since Microsoft Office Word is a widely used productivity tool that frequently handles documents received via email or network shares, this vulnerability presents a significant attack surface. The ability to execute code over a network means that an attacker does not need physical access to the target system; instead, they can exploit the flaw remotely by tricking a user into opening a malicious document.
The operational impact of successfully exploiting this vulnerability is severe and comprehensive. An unauthorized attacker who gains control through remote code execution typically achieves the same level of privileges as the current user running the application. This means that if a standard user opens the malicious file, the attacker can perform actions with those same limited rights, such as installing malware, stealing sensitive data stored on the local machine, or creating new accounts. However, if the victim is operating with administrative privileges, the compromise extends to full control over the system. The attacker could then pivot to other systems within the network, escalate privileges further, and establish persistent access for long-term espionage or disruption. This aligns with several tactics in the MITRE ATT&CK framework, particularly Initial Access through spearphishing attachment and Execution via user interaction, highlighting the social engineering aspect often required to trigger such vulnerabilities.
Mitigation strategies must address both immediate remediation and broader security hygiene. The most effective defense is to apply the official patches released by Microsoft as soon as they become available for the specific version of Office Word in use. Organizations should prioritize patch management processes to ensure that all endpoints are updated promptly, reducing the window of exposure. Additionally, implementing application control policies can restrict the execution of untrusted scripts or binaries from temporary folders where downloaded documents often reside. Users must be educated on safe computing practices, including verifying the source of email attachments and avoiding opening files from unknown senders. Network segmentation and endpoint detection and response solutions can also help in detecting anomalous behavior indicative of exploitation attempts, such as unusual process creation following document access, thereby providing an additional layer of defense against this class of memory corruption vulnerabilities.