EUVD-2026-73817
GHSA-c99c-vfp3-j237
Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Local delivery of crafted document with mandatory user open; attacker needs no system privileges; only confidentiality impacted via memory over-read, no integrity or availability effects.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
3DescriptionCVE.org
Improper null termination in Microsoft Office Word allows an unauthorized attacker to disclose information locally.
AnalysisAI
Improper null termination (CWE-170) in Microsoft Office Word's document-processing pipeline allows a local attacker to read beyond a string buffer boundary, disclosing sensitive in-memory data when a victim opens a crafted document. Affected products span Microsoft 365 Apps for Enterprise, Office 2019/2021/2024 LTSC, Word 2016, and Mac variants across Windows (x64/x86) and macOS. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires two concrete prerequisites: (1) the victim must open a specially crafted Word document using an unpatched installation of Microsoft Office Word (AV:L/UI:R), meaning the attacker must first deliver the malicious file to the target's filesystem via phishing, shared drive, USB, or another delivery mechanism; (2) the victim must actively open the file - passive or background processing is insufficient. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 3.1 score of 5.5 (Medium) is consistent with the actual threat profile: AV:L constrains exploitation to scenarios where the attacker can deliver a malicious document to the victim's local system, and UI:R mandates that the victim open that document. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | Full exploit scenario with step-by-step reproduction available after sign-in. |
| Remediation | Apply Microsoft's security update through Windows Update, Microsoft Update Catalog, or Microsoft AutoUpdate (macOS) to reach the following fixed builds: Microsoft 365 Apps for Enterprise to 16.0.20326.20136 or later; Office 2019 to 16.0.10417.20204 or later; Office LTSC 2021 to 16.0.14334.20896 or later; Office LTSC 2024 to 16.0.17932.20960 or later; Word 2016 to 16.0.5569.1000 or later. … Detailed patch versions, workarounds, and compensating controls in full report. |
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Same weakness CWE-170 – Improper Null Termination
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External POC / Exploit Code
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