EUVD-2026-56701
GHSA-v8rw-p6qg-h7qx
Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Local vector with mandatory user interaction to open the crafted file; no target-system privileges needed as attacker delivers the file externally via phishing.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Lifecycle Timeline
3DescriptionCVE.org
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
AnalysisAI
Local code execution in Microsoft Office affects all major editions across Windows and macOS, including Microsoft 365 Apps for Enterprise, Office LTSC 2021/2024, Office 2019, and their Mac counterparts. The vulnerability is a heap-based buffer overflow (CWE-122) triggered when a user opens a specially crafted document, granting the attacker arbitrary code execution at the victim's privilege level. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | The victim must open a specially crafted Microsoft Office document from the local file system - this is explicitly reflected in the CVSS vector as AV:L (local attack vector) and UI:R (user interaction required, specifically actively opening the file). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS base score of 7.8 reflects full confidentiality, integrity, and availability impact, consistent with arbitrary code execution in the context of the victim user. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker crafts a malicious Microsoft Office document embedding a specially structured payload that overflows a heap buffer in the Office file parser. The document is delivered to the victim via a phishing email or a compromised file-sharing link, and the victim opens it locally. … |
| Remediation | Apply the vendor-released patch immediately via Microsoft Update, the Microsoft Update Catalog, or Microsoft AutoUpdate on macOS. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, conduct an inventory of all Microsoft Office installations across Windows and macOS, including Office 2019, Office LTSC 2021/2024, and Microsoft 365 Apps for Enterprise, and establish patching timelines prioritizing mission-critical systems and high-risk departments. …
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Same weakness CWE-122 – Heap-based Buffer Overflow
View allSame technique Heap Overflow
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External POC / Exploit Code
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