Summary
Impact: Remote Code Execution. Microsoft rating: Important. Not known to be exploited — Exploitation Less Likely. Customer action: Required.
Details
How could an attacker exploit this vulnerability?
An attacker could provide a specially crafted Word document and convince a user to open it and export it to PDF. Successful exploitation could allow the attacker to execute code with the user's permissions. The attacker does not need an account on the affected system.
Is the Preview Pane an attack vector for this vulnerability?
No, the Preview Pane is not an attack vector.
Security updates
16.0.14334.21048 — https://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates
https — https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates
16.115.26110837 — https://learn.microsoft.com/en-us/officeupdates/release-notes-office-for-mac
Vulnerabilities 1
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High 8.8
Microsoft Office Word Remote Code Execution Vulnerability
Double free in Microsoft Office Word allows an unauthorized attacker to execute code over a network.
Revision history
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#1
Information published.
References
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CVE-2026-109503 Microsoft Office Word Remote Code Execution Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-109503
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Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
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Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
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Common Vulnerability Scoring System
https://www.first.org/cvss