CVE-2026-64911

Analyzed Analyzed - Analysis Complete

Integer Overflow in Microsoft Office Leads to Code Execution

Publication date: 2026-08-11

Last updated on: 2026-08-14

Assigner: Microsoft Corporation

Description

Integer overflow or wraparound in Microsoft Office allows an unauthorized attacker to execute code locally.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-08-11

Last Modified

2026-08-14

Generated

2026-09-01

AI Q&A

2026-08-11

EPSS Evaluated

2026-08-31

NVD

CVE-2026-64911

EUVD

EUVD-2026-56714

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	365_apps	*
microsoft	365_apps	*
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-122	A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
CWE-190	The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

Attack-Flow Graph

Executive Summary

This vulnerability is an integer overflow or wraparound flaw in Microsoft Office. It allows an unauthorized attacker to execute arbitrary code on a local system by exploiting how the software handles integer calculations.

Detection Guidance

This vulnerability involves an integer overflow in Microsoft Office that could allow remote code execution. Detection typically requires checking for specific Office versions or applying Microsoft's security updates. Use Microsoft's official tools like the Microsoft Update Catalog or Windows Update to verify patch status. No direct command is provided in the context to detect this specific issue.

Impact Analysis

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

Compliance Impact

This vulnerability allows unauthorized code execution, which could lead to unauthorized access to sensitive data. This may violate compliance requirements under GDPR (data protection) and HIPAA (health information security) by enabling data breaches or unauthorized processing.

Mitigation Strategies

Apply the latest security updates from Microsoft Office immediately to patch the integer overflow vulnerability. Monitor Microsoft's official update guide for patches and disable Office macros if not required.

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