CVE-2026-44817: Microsoft Excel Remote Code Execution Vulnerability

Published Jun 9, 2026
·
Updated

Access of resource using incompatible type ('type confusion') in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

Other sources

Microsoft Excel Remote Code Execution Vulnerability

Microsoft

Affected Software

28 affected componentsFixes available
Microsoft 365 Apps
Microsoft 365 Apps
Microsoft Excel=2016
Microsoft Excel=2016
Microsoft Microsoft 365 Macos
Microsoft Office 2019
Microsoft Office 2019
Microsoft Office 2021
Microsoft Office 2021
Microsoft Office 2021 Macos
Microsoft Office 2024
Microsoft Office 2024
Microsoft Office 2024 Macos
Microsoft Office Online Server
Microsoft Office LTSC 2024 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Excel 2016<16.0.5556.1001
16.0.5556.1001
Microsoft Office LTSC 2021 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft 365 Apps for Enterprise<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Excel 2016<16.0.5556.1001
16.0.5556.1001
Microsoft Office LTSC 2021 for 64-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office LTSC for Mac 2024<16.110.26061317
16.110.26061317
Microsoft Office LTSC 2024 for 64-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office LTSC for Mac 2021<16.110.26061317
16.110.26061317
Microsoft 365 Apps for Enterprise<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office Online Server<16.0.10417.20137
16.0.10417.20137
Microsoft Office 2019 for 64-bit editions<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 365 for Mac<16.110.26061317
16.110.26061317

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in https://aka.ms/OfficeSecurityReleases
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 16.0.5556.1001Patch KB5002877
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 16.110.26061317
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 16.0.10417.20137Patch KB5002875

Event History

Jun 9, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·05:04 PM
Data Sourced
via MITRE·05:04 PM
DescriptionSeverity
Data Sourced
via NVD·05:17 PM
DescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-44817?

CVE-2026-44817 has a high severity rating of 7.8.

2

What vulnerability type is CVE-2026-44817?

CVE-2026-44817 is classified as a remote code execution vulnerability in Microsoft Excel.

3

How do I fix CVE-2026-44817?

To fix CVE-2026-44817, install the latest security updates for Microsoft Excel provided by Microsoft.

4

What software is affected by CVE-2026-44817?

CVE-2026-44817 affects Microsoft Excel 2016, Microsoft 365 Apps for Enterprise, Microsoft Office Online Server, Microsoft Office 2019, Microsoft Office 2021, and Microsoft Office 2024.

5

What is the potential impact of CVE-2026-44817?

The potential impact of CVE-2026-44817 allows unauthorized code execution locally on affected systems.

Contact

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