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MicrosoftCVE-2026-70329

Microsoft Office Outlook: integer overflow

High8.8CVE-2026-70329 · Published Aug 11, 2026 · updated Aug 14, 2026

Integer overflow or wraparound in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network.

Microsoft advisory

Affected versions

PackageAffectedFixed in
Microsoft 365 Apps for Enterprise
Product
>= 16.0.1, < https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleases
Microsoft Office 2019
Product
>= 19.0.0, < https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleases
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 Outlook 2016
Product
>= 16.0.0.0, < 16.0.5565.100016.0.5565.1000
Details and references
CVSS 3.1
CVSS:3.1/AV:N/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-190

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