CVE-2026-55898

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 disclose information locally.

CVSS Scores

EPSS Scores

Probability:
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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-2026-55898

EUVD

EUVD-2026-44228

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 access and disclose information stored locally on a system by exploiting a flaw in how Excel processes certain data.

Detection Guidance

This vulnerability is an out-of-bounds read in Microsoft Office Excel that allows local information disclosure. Detection typically involves checking for vulnerable versions of Microsoft Excel or Office applications and applying security updates. Use Windows Update or check installed versions via 'Control Panel > Programs > Programs and Features' for Office products.

Impact Analysis

An attacker could exploit this to read sensitive data from your system, such as files or memory contents, potentially leading to unauthorized access to confidential information.

Compliance Impact

This vulnerability could lead to unauthorized data disclosure, which may violate GDPR or HIPAA requirements for protecting personal or health information. Organizations must address it to maintain compliance.

Mitigation Strategies

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

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