CVE-2026-40367: Microsoft Word Remote Code Execution Vulnerability

Published May 12, 2026
·
Updated

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

Other sources

Microsoft Word Remote Code Execution Vulnerability

Microsoft

Affected Software

30 affected componentsFixes available
Microsoft 365 Apps
Microsoft 365 Apps
Microsoft Office=2019
Microsoft Office=2019
Microsoft Office Long Term Servicing Channel=2021
Microsoft Office Long Term Servicing Channel=2021
Microsoft Office Long Term Servicing Channel Macos=2021
Microsoft Office Long Term Servicing Channel=2024
Microsoft Office Long Term Servicing Channel=2024
Microsoft Office Long Term Servicing Channel Macos=2024
Microsoft SharePoint Server<16.0.19725.20280
Microsoft SharePoint Server=2016
Microsoft SharePoint Server=2019
Microsoft Word=2016
Microsoft Word=2016
Microsoft Word 2016<16.0.5552.1000
16.0.5552.1000
Microsoft Office LTSC 2024 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 Word 2016<16.0.5552.1000
16.0.5552.1000
Microsoft Office 2019 for 64-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 Office LTSC for Mac 2024<16.109.26051019
16.109.26051019
Microsoft SharePoint Server 2019<16.0.10417.20128
16.0.10417.20128
Microsoft Office 2019 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office LTSC for Mac 2021<16.109.26051019
16.109.26051019
Microsoft Office LTSC 2021 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft SharePoint Server Subscription Edition<16.0.19725.20280
16.0.19725.20280
Microsoft 365 Apps for Enterprise<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft SharePoint Enterprise Server 2016<16.0.5552.1002
16.0.5552.1002
Microsoft Office LTSC 2024 for 64-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases

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 16.0.5552.1000Patch KB5002858
  3. Upgrade

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

    Fixed in 16.0.10417.20128Patch KB5002872
  4. Upgrade

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

    Fixed in 16.109.26051019
  5. Upgrade

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

    Fixed in 16.0.19725.20280Patch KB5002863
  6. Upgrade

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

    Fixed in 16.0.5552.1002Patch KB5002869

Event History

May 12, 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
DescriptionSeverity
CVE Published
via MITRE·04:59 PM
Data Sourced
via MITRE·04:59 PM
DescriptionSeverity
Data Sourced
via NVD·06:17 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-40367?

CVE-2026-40367 is classified as a critical severity vulnerability due to its potential for remote code execution.

2

How do I fix CVE-2026-40367?

To fix CVE-2026-40367, ensure that you apply the latest security updates provided by Microsoft for the affected versions of Word and Office.

3

Which versions of Microsoft Word are affected by CVE-2026-40367?

CVE-2026-40367 affects multiple versions of Microsoft Word including Word 2016, Office LTSC 2021 and 2024, and Office 2019.

4

Can CVE-2026-40367 be exploited remotely?

Yes, CVE-2026-40367 can be exploited remotely by an attacker through untrusted pointer dereference.

5

What type of vulnerability is CVE-2026-40367?

CVE-2026-40367 is a remote code execution vulnerability that allows unauthorized execution of code via Microsoft Word.

Contact

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