CVE-2026-64903: Microsoft Office Remote Code Execution Vulnerability

Published Aug 11, 2026
·
Updated

Integer overflow or wraparound in Microsoft Office allows an unauthorized attacker to execute code locally.

Other sources

Microsoft Office Remote Code Execution Vulnerability

Microsoft

Affected Software

13 affected componentsFixes available
Microsoft Office LTSC for Mac 2024<16.112.26081010
16.112.26081010
Microsoft Office LTSC 2021 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 LTSC 2024 for 64-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office 2016<16.0.5565.1001
16.0.5565.1001
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 LTSC for Mac 2021<16.112.26081010
16.112.26081010
Microsoft Office 365 for Mac<16.112.26081010
16.112.26081010
Microsoft Office 2019 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office 2016<16.0.5565.1001
16.0.5565.1001
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

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 16.112.26081010
  2. Upgrade

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

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

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

    Fixed in 16.0.5565.1001Patch KB5002897

Event History

Aug 11, 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·05:06 PM
Data Sourced
via MITRE·05:06 PM
DescriptionSeverity
Data Sourced
via NVD·05:18 PM
DescriptionSeverityWeakness
Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is the severity of CVE-2026-64903?

The severity of CVE-2026-64903 is rated high with a score of 7.8.

2

How does CVE-2026-64903 affect Microsoft Office?

CVE-2026-64903 allows an unauthorized attacker to execute code locally through an integer overflow vulnerability in Microsoft Office.

3

Which versions of Microsoft Office are vulnerable to CVE-2026-64903?

CVE-2026-64903 affects Microsoft Office 2016, Microsoft 365 Apps for Enterprise, Microsoft Office LTSC for Mac 2024, and various editions of Microsoft Office LTSC 2021 and 2024.

4

How do I fix CVE-2026-64903?

To fix CVE-2026-64903, ensure that you apply the latest security updates provided by Microsoft for your affected Office application.

5

Can exploiting CVE-2026-64903 lead to data loss?

Yes, exploiting CVE-2026-64903 could potentially lead to data loss since it allows for remote code execution, which may compromise system integrity.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203