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MicrosoftCVE-2026-78506

Microsoft Office Word: unauthorized attacker could disclose information locally

Medium5.5CVE-2026-78506 · Published Sep 8, 2026 · updated Sep 17, 2026

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

Microsoft advisory

Affected versions

PackageAffectedFixed in
Microsoft 365 Apps for Enterprise
Product
>= 16.0.1, < 16.0.20326.2013816.0.20326.20138
Microsoft Office 2019
Product
>= 19.0.0, < 16.0.10417.2020716.0.10417.20207
Microsoft Office 365 for Mac
Product
>= 1.0.0, < 16.113.2609143316.113.26091433
Microsoft Office LTSC 2021
Product
>= 16.0.1, < 16.0.14334.2090616.0.14334.20906
Microsoft Office LTSC 2024
Product
>= 16.0.0, < 16.0.17932.2097616.0.17932.20976
Microsoft Office LTSC for Mac 2021
Product
>= 16.0.1, < 16.113.2609143316.113.26091433
Microsoft Office LTSC for Mac 2024
Product
>= 16.0.0, < 16.113.2609143316.113.26091433
Microsoft Word 2016
Product
>= 16.0.1, < 16.0.5569.100016.0.5569.1000
Details and references
CVSS 3.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Severity from
the vendor (its own CVE record or advisory)
Weakness
CWE-170

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