EUVD-2026-56568
GHSA-q435-q689-9ppx
Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
AV:L and UI:R reflect document-open delivery; PR:N because no system account privilege is needed; S:U as code runs in Word process only.
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
Use after free in Microsoft Office Word allows an unauthorized attacker to execute code locally.
AnalysisAI
Use-after-free memory corruption in Microsoft Office Word enables local code execution when a user opens a specially crafted document. The CVSS vector (AV:L/AC:L/PR:N/UI:R) confirms this is a social-engineering-dependent attack - no system privileges are required, but the victim must open a malicious file, making phishing or drive-by document delivery the likely delivery mechanism. …
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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 Word document - this is the sole prerequisite confirmed by the CVSS UI:R and AV:L metrics. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 7.8 High score is well-supported by the vector: AV:L reduces automated internet-scale exploitation, but UI:R paired with AV:L in the Office context is effectively synonymous with a phishing document - a trivially achievable delivery mechanism in enterprise environments. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker crafts a malicious Word document that triggers a specific heap allocation and deallocation sequence during file parsing, leaving a dangling pointer that the attacker can cause to reference attacker-controlled heap memory. The document is delivered via a phishing email or malicious download; when the victim opens it in Microsoft Office Word, the use-after-free condition is triggered, redirecting execution to shellcode or a ROP chain, achieving arbitrary code execution in the context of the victim's user account. … |
| Remediation | Apply the Microsoft security update published for CVE-2026-70311 via the Microsoft Update Catalog or Windows Update; the exact patched version must be retrieved from the MSRC advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70311, as no specific fix version was included in the available intelligence. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, conduct emergency inventory of Word installations across all user endpoints and distribution lists; notify users via email and security brief that opening Word documents from untrusted sources presents immediate risk, with emphasis on external communications and file-sharing platforms. …
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Same weakness CWE-416 – Use After Free
View allSame technique Use After Free
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External POC / Exploit Code
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