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MicrosoftCVE-2026-64918

Microsoft Office: spoofing

Medium6.5CVE-2026-64918 · Published Sep 8, 2026 · updated Sep 9, 2026

Insufficiently protected credentials in Microsoft Office allows an unauthorized attacker to perform spoofing 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 2016
Product
>= 16.0.0, < 16.0.5569.100316.0.5569.1003
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
Details and references
CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Severity from
the vendor (its own CVE record or advisory)
Weakness
CWE-522

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