Use After Free in Microsoft Office Word Allows Code Execution

Publication date: 2026-09-08

Last updated on: 2026-09-09

Assigner: Microsoft Corporation

Description

Use after free in Microsoft Office Word allows an unauthorized attacker to execute code over a network.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-08

Last Modified

2026-09-09

Generated

2026-09-29

AI Q&A

2026-09-10

EPSS Evaluated

2026-09-27

NVD

CVE-2026-78514

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	365_apps	*
microsoft	365_apps	*
microsoft	word	2016
microsoft	word	2016
microsoft	office_2019	*
microsoft	office_2019	*
microsoft	microsoft_365	*
microsoft	office_2021	*
microsoft	office_2021	*
microsoft	office_2021	*
microsoft	office_2024	*
microsoft	office_2024	*
microsoft	office_2024	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-416	The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

Executive Summary

This is a use-after-free vulnerability in Microsoft Office Word. It allows an unauthorized attacker to execute arbitrary code remotely by exploiting a memory management flaw where freed memory is accessed improperly.

Impact Analysis

An attacker could exploit this to run malicious code on your system, potentially stealing data, installing malware, or taking control of your computer. It requires user interaction like opening a specially crafted document.

Mitigation Strategies

Apply the latest security updates from Microsoft for Microsoft Office Word and related applications as soon as possible to patch the use-after-free vulnerability.

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