CVE-2026-55031

Analyzed Analyzed - Analysis Complete

Out-of-Bounds Read in Microsoft Office Excel

Publication date: 2026-07-14

Last updated on: 2026-07-15

Assigner: Microsoft Corporation

Description

Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-07-14

Last Modified

2026-07-15

Generated

2026-08-04

AI Q&A

2026-07-15

EPSS Evaluated

2026-08-02

NVD

CVE-2026-55031

EUVD

EUVD-2026-44172

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	365_apps	*
microsoft	365_apps	*
microsoft	excel	2016
microsoft	excel	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	office_online_server	to 16.0.10417.20175 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-125	The product reads data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

This is an out-of-bounds read vulnerability in Microsoft Office Excel. It allows an unauthorized attacker to execute arbitrary code on a local system by exploiting memory access beyond allocated bounds.

Detection Guidance

Detection of CVE-2026-55031 requires monitoring for unusual Excel file processing or crashes. Check for Excel application logs for out-of-bounds read errors or unexpected termination. Use process monitoring tools like Process Explorer to observe Excel.exe behavior for suspicious memory access patterns.

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 if you open a specially crafted Excel file.

Compliance Impact

This vulnerability allows unauthorized code execution via an out-of-bounds read in Microsoft Office Excel. Such attacks could lead to unauthorized access to sensitive data, which may violate GDPR's data protection requirements or HIPAA's safeguards for protected health information if exploited.

Mitigation Strategies

Apply the latest security updates from Microsoft for Excel as soon as possible to patch the out-of-bounds read vulnerability.

Hi! I’m here to help you understand CVE-2026-55031. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70