CVE-2026-66806: Microsoft Office Word Information Disclosure Vulnerability

Published Aug 11, 2026
·
Updated

Microsoft Office Word Information Disclosure Vulnerability

Other sources

Off-by-one error in Microsoft Office Word allows an unauthorized attacker to disclose information locally.

Microsoft

Affected Software

10 affected componentsFixes available
Microsoft Office LTSC 2024 for 64-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Word 2016<16.0.5565.1000
16.0.5565.1000
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
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<16.0.5565.1000
16.0.5565.1000
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

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 16.0.5565.1000Patch KB5002901

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·05:07 PM
Data Sourced
via MITRE·05:07 PM
DescriptionSeverity
Data Sourced
via NVD·05:19 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-2026-66806?

CVE-2026-66806 has a medium severity rating of 5.5.

2

How do I fix CVE-2026-66806?

To address CVE-2026-66806, ensure you apply the latest security updates provided by Microsoft for your version of Microsoft Word.

3

Which software is affected by CVE-2026-66806?

CVE-2026-66806 affects several versions including Microsoft Word 2016, Microsoft 365 Apps for Enterprise, Microsoft Office 2019, and Microsoft Office LTSC editions.

4

What type of vulnerability is CVE-2026-66806?

CVE-2026-66806 is classified as an information disclosure vulnerability due to an off-by-one error in Microsoft Office Word.

5

Can CVE-2026-66806 be exploited remotely?

CVE-2026-66806 requires local access, meaning it cannot be exploited remotely.

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