CVE-2026-55054

Microsoft Excel Information Disclosure Vulnerability

State: Published
Severity: 6.5 Medium
Published: Jul 14, 2026
Updated: Nov 1, 2026
Reserved: Jun 16, 2026

Description

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

Scores

CVSS	Score	Vector	Source
3.1	6.5 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/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 16.0.5561.1001Affected
Microsoft Office 2019Microsoft	19.0.0 to before https://aka.ms/OfficeSecurityReleasesAffected
Microsoft Office 365 for MacMicrosoft	1.0.0 to before 16.111.26071215Affected
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 16.111.26071215Affected
Microsoft Office LTSC for Mac 2024Microsoft	16.0.0 to before 16.111.26071215Affected
Office Online ServerMicrosoft	16.0.0.0 to before 16.0.10417.20175Affected

References

Microsoft Excel Information Disclosure Vulnerabilityvendor-advisorypatch

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.