EUVD-2026-56764
GHSA-rhm8-v74c-45m2
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Local trigger requiring only a standard user account, no user interaction, achieving full code execution - PR:L and AV:L are independently justified by CVSS vector and SSVC non-automatable finding.
Primary rating from Vendor (microsoft).
CVSS VectorNVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
5DescriptionNVD
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
AnalysisAI
Heap-based buffer overflow in Microsoft Office (365 Apps for Enterprise, Office 2019, Office 2021 LTSC, and Office 2024 LTSC) enables a local attacker with low-privilege credentials to execute arbitrary code with the full confidentiality, integrity, and availability impact of the Office process. The vulnerability (CWE-122) carries a CVSS 3.1 score of 7.8 and requires only local access and a standard user account - no user interaction is needed once the attacker can trigger the vulnerable allocation path. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | The CVSS vector (AV:L/PR:L) confirms that exploitation requires an attacker to already have local access to the target system with at least a low-privilege user account - remote unauthenticated exploitation is not possible. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 3.1 score of 7.8 (High) is driven by local attack vector (AV:L), low complexity (AC:L), low privilege requirement (PR:L), no user interaction (UI:N), and total impact across confidentiality, integrity, and availability (C:H/I:H/A:H). … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | A local attacker with a standard (low-privilege) Windows user account on a host running an affected Office version triggers the vulnerable heap allocation path - for example, by opening a crafted document or invoking a vulnerable Office function - causing a heap buffer overflow that corrupts adjacent memory. The attacker uses this corruption to overwrite a control-flow structure and redirect execution to attacker-controlled code running at the privilege level of the Office process. … |
| Remediation | Patch available per vendor advisory - apply the latest cumulative Office update via Microsoft Update, Windows Update, or the Microsoft Update Catalog, referencing https://aka.ms/OfficeSecurityReleases for product-specific guidance. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours: Inventory all Office versions in use across the environment, particularly 365 Apps for Enterprise, Office 2019, 2021 LTSC, and 2024 LTSC; establish monitoring for suspicious Office process behavior and unexpected child process spawning. …
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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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