Out-of-bounds Read in Microsoft Office Excel

Publication date: 2026-09-08

Last updated on: 2026-09-09

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:
Percentile:

Meta Information

Published

2026-09-08

Last Modified

2026-09-09

Generated

2026-09-29

AI Q&A

2026-09-09

EPSS Evaluated

2026-09-27

NVD

CVE-2026-81400

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	office_2016	*
microsoft	office_2016	*
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-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 read memory outside the intended buffer, potentially exposing sensitive information stored locally on the system.

Impact Analysis

An attacker could exploit this to access confidential data stored on your computer, such as files opened in Excel or other sensitive memory contents. This could lead to unauthorized information disclosure.

Mitigation Strategies

Apply the latest security updates from Microsoft for Excel to patch the out-of-bounds read vulnerability. Monitor Microsoft's official security advisories for updates and disable Excel macros if not required.

Hi! I’m here to help you understand CVE-2026-81400. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70