EUVD-2026-56419
GHSA-2xm7-6xcv-jfx8
Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Local vector because exploitation requires user to open a delivered document; no privileges needed; full CIA impact on the process scope.
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
Heap-based buffer overflow in Microsoft Office enables local code execution with high impact across confidentiality, integrity, and availability. Affecting Office 2016 through 2024, including LTSC and Microsoft 365 variants on both Windows and macOS, the vulnerability is triggered when a user opens a specially crafted document - requiring no privileges but mandatory user interaction (CVSS AV:L/UI:R). …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires that the victim open a specially crafted Office document on a system running a vulnerable version of Microsoft Office - user interaction is mandatory (UI:R in the CVSS vector). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 3.1 score of 7.8 (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) reflects a realistic threat model: low attack complexity and no privilege requirement offset by the mandatory user interaction gate. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker crafts a malicious Office document (such as a .docx, .xlsx, or .pptx file) that embeds a specially structured record designed to trigger the heap-based buffer overflow in Microsoft Office's parsing engine. The document is delivered to a target via phishing email or malicious download; when the victim opens it with a vulnerable Office version, the overflow corrupts heap memory, enabling the attacker to redirect execution flow and run arbitrary code under the victim's user context. … |
| Remediation | The primary fix is to apply Microsoft's released patches for each affected product. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, identify all Office 2016, 2019, 2021, and 2024 installations plus Microsoft 365 deployments in your environment and obtain the patch from Microsoft. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
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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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