Summary
Impact: Remote Code Execution. Microsoft rating: Important. Not known to be exploited — Exploitation Less Likely. Customer action: Required.
Details
According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?
Successful exploitation requires a specially crafted document that causes unusually large memory operations in the affected application. Exploitation depends on memory conditions that the attacker cannot fully control.
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 7.5
Microsoft Office Word Remote Code Execution Vulnerability
Heap-based buffer overflow 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-2026-109500 Microsoft Office Word Remote Code Execution Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-109500
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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