CVE-2026-40360

Microsoft Excel Information Disclosure Vulnerability

State: Published
Severity: 7.8 High
Published: May 12, 2026
Updated: Aug 10, 2026
Reserved: Apr 11, 2026

Description

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

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C	microsoft

Weaknesses

CWE-125 Out-of-bounds Read

Affected Products

Product	Versions
Microsoft 365 Apps for EnterpriseMicrosoft	16.0.1 to before https://aka.ms/OfficeSecurityReleasesAffected
Microsoft Excel 2016Microsoft	16.0.0.0 to before 16.0.5552.1000Affected
Microsoft Office 2019Microsoft	19.0.0 to before https://aka.ms/OfficeSecurityReleasesAffected
Microsoft Office LTSC 2021Microsoft	16.0.1 to before https://aka.ms/OfficeSecurityReleasesAffected
Microsoft Office LTSC 2024Microsoft	16.0.0 to before https://aka.ms/OfficeSecurityReleasesAffected
Microsoft Office LTSC for Mac 2021Microsoft	16.0.1 to before 16.109.26051019Affected
Microsoft Office LTSC for Mac 2024Microsoft	16.0.0 to before 16.109.26051019Affected
Office Online ServerMicrosoft	16.0.0.0 to before 16.0.10417.20128Affected

References

Microsoft Excel Information Disclosure Vulnerabilityvendor-advisorypatch

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