CVE-2026-40361: Microsoft Outlook and Word Remote Code Execution Vulnerability

Published May 12, 2026
·
Updated

Microsoft Outlook and Word Remote Code Execution Vulnerability

Other sources

Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.

Microsoft

Affected Software

24 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 Word=2016
Microsoft Word=2016
Microsoft Office LTSC 2021 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Word 2016<16.0.5552.1000
16.0.5552.1000
Microsoft Office LTSC for Mac 2024<16.109.26051019
16.109.26051019
Microsoft Office LTSC 2024 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office LTSC 2024 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 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 LTSC for Mac 2021<16.109.26051019
16.109.26051019
Microsoft Office 2019 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 Office 2019 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 16.109.26051019

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
Description
CVE Published
via MITRE·04:59 PM
Data Sourced
via MITRE·04:59 PM
DescriptionSeverity
Data Sourced
via NVD·06:17 PM
DescriptionSeverityWeaknessAffected Software
News Published
via Dark Reading·09:03 PM
May 13, 2026
News Published
via Dark Reading·12:06 PM
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Frequently Asked Questions

1

What is the severity of CVE-2026-40361?

The severity of CVE-2026-40361 is rated high with a score of 8.4.

2

How do I fix CVE-2026-40361?

To mitigate CVE-2026-40361, apply the latest security updates and patches provided by Microsoft for affected versions of Microsoft Word.

3

What types of software are affected by CVE-2026-40361?

CVE-2026-40361 affects Microsoft Office Long Term Servicing Channel, Microsoft Word 2016, Microsoft 365 Apps for Enterprise, and other versions of Microsoft Office.

4

What is the impact of CVE-2026-40361?

CVE-2026-40361 allows an unauthorized attacker to execute code locally through a use after free vulnerability in Microsoft Word.

5

When was CVE-2026-40361 published?

CVE-2026-40361 was published on May 12, 2026.

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