CVE-2026-78526: Microsoft Office Word Remote Code Execution Vulnerability

Published Sep 8, 2026
·
Updated

Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.

Other sources

Microsoft Office Word Remote Code Execution Vulnerability

Microsoft

Affected Software

13 affected componentsFixes available
Microsoft Office LTSC 2024 for 32-bit editions<16.0.17932.20960
16.0.17932.20960
Microsoft Office LTSC 2024 for 64-bit editions<16.0.17932.20960
16.0.17932.20960
Microsoft Office 365 for Mac
Microsoft Office 2019 for 64-bit editions<16.0.10417.20204
16.0.10417.20204
Microsoft Office LTSC 2021 for 32-bit editions<16.0.14334.20896
16.0.14334.20896
Microsoft Office LTSC 2021 for 64-bit editions<16.0.14334.20896
16.0.14334.20896
Microsoft Office LTSC for Mac 2021
Microsoft Office 2016<16.0.5569.1002
16.0.5569.1002
Microsoft Office 2016<16.0.5569.1002
16.0.5569.1002
Microsoft Office LTSC for Mac 2024
Microsoft 365 Apps for Enterprise<16.0.20326.20136
16.0.20326.20136
Microsoft 365 Apps for Enterprise<16.0.20326.20136
16.0.20326.20136
Microsoft Office 2019 for 32-bit editions<16.0.10417.20204
16.0.10417.20204

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 16.0.17932.20960
  2. Upgrade

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

    Fixed in 16.0.10417.20204
  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 16.0.5569.1002Patch KB5002898
  5. Upgrade

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

    Fixed in 16.0.20326.20136

Event History

Sep 8, 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·05:18 PM
Data Sourced
via MITRE·05:18 PM
DescriptionSeverity

Frequently Asked Questions

1

Does exploitation require an authenticated Office account or other attacker privileges?

No attacker privileges are required. Exploitation requires user interaction, so an attacker would need a user to interact with the malicious content or request.

2

Which Office products are listed as affected?

The affected software list includes Microsoft Office 2016, Microsoft 365 Apps for Enterprise, Office LTSC 2021 and 2024 in 32-bit and 64-bit editions, Office 2019 for 64-bit editions, and Microsoft Office 365 for Mac.

Contact

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