Summary
Impact: Information Disclosure. Microsoft rating: Important. Not known to be exploited — Exploitation Less Likely. Customer action: Required.
Details
According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?
An attacker must send a user a malicious Office file and convince them to open it.
Is the Preview Pane an attack vector for this vulnerability?
Yes, the Preview Pane is an attack vector.
What type of information could be disclosed by this vulnerability?
An attacker who successfully exploited this vulnerability could potentially read small portions of heap memory.
Security updates
16.0.5569.1000 — https://support.microsoft.com/help/5002923
16.0.10417.20207 — https://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates
16.0.20326.20138 — https://docs.microsoft.com/en-us/officeupdates/office365-proplus-security-updates
Vulnerabilities 1
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Medium 5.5
Microsoft Office Word Information Disclosure Vulnerability
Buffer over-read in Microsoft Office Word allows an unauthorized attacker to disclose information locally.
Revision history
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#1
Information published.
References
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CVE-2026-83949 Microsoft Office Word Information Disclosure Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83949
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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