CVE-2026-78506: Microsoft Office Word Information Disclosure Vulnerability

Published Sep 8, 2026
·
Updated

Improper null termination in Microsoft Office Word allows an unauthorized attacker to disclose information locally.

Other sources

Microsoft Office Word Information Disclosure Vulnerability

Microsoft

Affected Software

14 affected componentsFixes available
Microsoft Word 2016<16.0.5569.1000
16.0.5569.1000
Microsoft Office 365 for Mac
Microsoft Office LTSC 2024 for 32-bit editions<16.0.17932.20960
16.0.17932.20960
Microsoft Office LTSC 2021 for 64-bit editions<16.0.14334.20896
16.0.14334.20896
Microsoft Office LTSC for Mac 2021
Microsoft Office LTSC 2021 for 32-bit editions<16.0.14334.20896
16.0.14334.20896
Microsoft 365 Apps for Enterprise<16.0.20326.20136
16.0.20326.20136
Microsoft Word 2016<16.0.5569.1000
16.0.5569.1000
Microsoft Office LTSC 2024 for 64-bit editions<16.0.17932.20960
16.0.17932.20960
Microsoft 365 Apps for Enterprise<16.0.20326.20136
16.0.20326.20136
Microsoft Office 2019 for 64-bit editions<16.0.10417.20204
16.0.10417.20204
Microsoft Office LTSC for Mac 2024
Microsoft Office 2019 for 32-bit editions<16.0.10417.20204
16.0.10417.20204
Microsoft Office Word

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 16.0.5569.1000Patch KB5002923
  2. Upgrade

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

    Fixed in 16.0.17932.20960
  3. Upgrade

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

    Fixed in 16.0.14334.20896
  4. Upgrade

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

    Fixed in 16.0.20326.20136
  5. Upgrade

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

    Fixed in 16.0.10417.20204

Event History

Sep 8, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·05:18 PM
Data Sourced
via MITRE·05:18 PM
DescriptionSeverity

Frequently Asked Questions

1

Which Word deployments are identified as affected?

The listed affected products are Word 2016, Microsoft 365 Apps for Enterprise, Office 365 for Mac, Office LTSC 2021 for 32-bit and 64-bit editions and for Mac, and Office LTSC 2024 for 32-bit and 64-bit editions.

2

What access and user interaction does exploitation require?

The vector is local and no privileges are required. User interaction is required, but the available data does not specify what action the user must take.

3

What is the expected security impact?

Successful exploitation can disclose information. The supplied severity vector indicates high confidentiality impact, with no integrity or availability impact.

Contact

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