Summary
Impact: Remote Code Execution. Microsoft rating: Critical. Not known to be exploited — Exploitation Less Likely. Customer action: Required.
Details
How could an attacker exploit this vulnerability?
An attacker could send a specially crafted WordPerfect document with a linked graphics file to a target user. The vulnerability can be triggered when Microsoft Word processes the document in the Reading Pane; the user does not need to open the document. Successful exploitation could allow the attacker to execute code on the user's system. Authentication is not required.
Is the Preview Pane an attack vector for this vulnerability?
Yes, the Preview Pane is an attack vector.
Security updates
https — https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates
16.0.14334.20974 — https://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates
Vulnerabilities 1
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Critical 9.8
Microsoft Office Word Remote Code Execution Vulnerability
Untrusted pointer dereference 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-2026-70300 Microsoft Office Word Remote Code Execution Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70300
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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