CVE-2026-55128

Analyzed Analyzed - Analysis Complete

Use After Free in Microsoft Office Word Allows Code Execution

Publication date: 2026-07-14

Last updated on: 2026-07-16

Assigner: Microsoft Corporation

Description

Use after free in Microsoft Office Word allows an unauthorized attacker to execute code locally.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-07-14

Last Modified

2026-07-16

Generated

2026-08-04

AI Q&A

2026-07-15

EPSS Evaluated

2026-08-02

NVD

CVE-2026-55128

EUVD

EUVD-2026-44214

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	sharepoint_server	2019
microsoft	sharepoint_server	2016
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	*
microsoft	sharepoint_server	to 16.0.19725.20434 (exc)
microsoft	office_online_server	to 16.0.10417.20175 (exc)

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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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 vulnerability is a use-after-free issue in Microsoft Office Word. It allows an unauthorized attacker to execute arbitrary code on the affected system by exploiting memory corruption after the memory has been freed.

Detection Guidance

This vulnerability involves a use-after-free issue in Microsoft Office Word. Detection typically requires monitoring for suspicious Word processes or crashes. Check for unexpected Word.exe behavior, crashes, or memory corruption errors in system logs. Use tools like Process Explorer or Windows Event Viewer to inspect Word-related processes and crashes.

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, such as opening a specially crafted document.

Compliance Impact

This vulnerability could lead to unauthorized access or data breaches, which may violate GDPR or HIPAA requirements for data protection and security. Organizations must address it to maintain compliance.

Mitigation Strategies

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

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