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MicrosoftCVE-2026-55048

Microsoft Office Excel: integer overflow

High7.8CVE-2026-55048 · Published Jul 14, 2026 · updated Jul 15, 2026

Integer overflow or wraparound in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

Microsoft advisory

Affected versions

PackageAffectedFixed in
Microsoft 365 Apps for Enterprise
Product
>= 16.0.1, < https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleases
Microsoft Excel 2016
Product
>= 16.0.0.0, < 16.0.5561.100116.0.5561.1001
Microsoft Office 2019
Product
>= 19.0.0, < https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleases
Microsoft Office 365 for Mac
Product
>= 1.0.0, < 16.111.2607121516.111.26071215
Microsoft Office LTSC 2021
Product
>= 16.0.1, < https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleases
Microsoft Office LTSC 2024
Product
>= 16.0.0, < https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleases
Microsoft Office LTSC for Mac 2021
Product
>= 16.0.1, < 16.111.2607121516.111.26071215
Microsoft Office LTSC for Mac 2024
Product
>= 16.0.0, < 16.111.2607121516.111.26071215
Office Online Server
Product
>= 16.0.0.0, < 16.0.10417.2017516.0.10417.20175
Details and references
CVSS 3.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Severity from
the vendor (its own CVE record or advisory)
Weakness
CWE-122, CWE-190

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