EUVD-2026-56432
GHSA-72mj-qw76-gff7
Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
AV:L because the malicious file must be locally opened; PR:N since no prior authentication is needed; UI:R because the user must open the crafted document to trigger the overflow.
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 arbitrary local code execution when a user opens a specially crafted document. Affected products span seven product lines across Windows and macOS, including Office 2019, Office LTSC 2021/2024, Microsoft 365 Apps for Enterprise, and their Mac counterparts, all prior to the vendor-released patch. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires an unpatched version of Microsoft Office (across any of the seven listed product lines) and that the local user opens a specially crafted Office document. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 3.1 score of 7.8 with vector AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H accurately reflects the risk profile: no prior privileges are required, attack complexity is low, but local file access and user interaction are both necessary. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker sends a phishing email to a target employee with a crafted Office document (e.g., a Word or Excel file) as an attachment. When the victim opens the file with an unpatched Office installation, the document parser triggers a heap-based buffer overflow, allowing the attacker to execute arbitrary code in the context of the victim's user session. … |
| Remediation | The primary fix is to apply the vendor-released patch immediately. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, enumerate all Office installations and versions across Windows and macOS endpoints to establish patching scope and prioritize high-risk user populations. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
Microsoft Outlook Remote Code Execution Vulnerability. Rated critical severity (CVSS 9.8), this vulnerability is remotel
Microsoft Excel Security Feature Bypass Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authenti
Microsoft Publisher Security Feature Bypass Vulnerability. Rated high severity (CVSS 7.3), this vulnerability is low att
Microsoft Office contains a security feature bypass (CVE-2026-21509, CVSS 7.8) where reliance on untrusted inputs in sec
Microsoft Office Word contains a security decision bypass (CVE-2026-21514, CVSS 7.8) through reliance on untrusted input
Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vu
Microsoft Office Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentic
Microsoft Excel Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentica
Use-after-free vulnerability in Microsoft Office Word that allows local, unauthenticated attackers to execute arbitrary
Microsoft Excel Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely expl
Microsoft Office Elevation of Privilege Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is low attack
A remote code execution vulnerability exists in Microsoft Excel software when the software fails to properly handle obje
Same weakness CWE-122 – Heap-based Buffer Overflow
View allSame technique Heap Overflow
View allShare
External POC / Exploit Code
Leaving vuln.today