CVE-2026-64918: Microsoft Office Spoofing Vulnerability
Published Sep 8, 2026
·Updated
Insufficiently protected credentials in Microsoft Office allows an unauthorized attacker to perform spoofing over a network.
Affected Software
20 affected componentsFixes available
Microsoft Office 2016<16.0.5569.1003
16.0.5569.1003
Microsoft Office LTSC 2024 for 64-bit editions<16.0.17932.20960
16.0.17932.20960
Microsoft Office 2016<16.0.5569.1003
16.0.5569.1003
Microsoft Office LTSC 2021 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office LTSC 2021 for 64-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft 365 Apps for Enterprise<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office 2019 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office LTSC 2024 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office 2019 for 64-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft 365 Apps for Enterprise<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft 365 Apps
Microsoft 365 Apps
Microsoft Office 2016
Microsoft Office 2016
Microsoft Office 2019
Microsoft Office 2019
Microsoft Office 2021
Microsoft Office 2021
Microsoft Office 2024
Microsoft Office 2024
Remediation
Event History
Sep 8, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·05:16 PM
Data Sourced
via MITRE·05:16 PM
DescriptionSeverity
Data Sourced
via NVD·06:18 PM
RemedyDescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
Which Office deployments are listed as affected?
The listed products are Microsoft Office 2016, Microsoft 365 Apps for Enterprise, Office 2019 for 32-bit and 64-bit editions, Office LTSC 2021 for 32-bit and 64-bit editions, and Office LTSC 2024 for 32-bit and 64-bit editions.
2
Does exploitation require an authenticated Office user or prior privileges?
No prior privileges are required (PR:N). The attack is network-based and requires user interaction (AV:N, UI:R).
3
What is the expected security impact if exploitation succeeds?
The vulnerability is rated medium severity with a 6.5 CVSS score. It has high confidentiality impact, while integrity and availability impact are rated none.