EUVD-2026-56692
GHSA-v9pm-wvgr-wxq5
Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Local vector reflects file-based delivery model; PR:N because no credentials are needed; UI:R because the user must open the crafted document; full C/I/A impact from arbitrary code execution.
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
Stack-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
AnalysisAI
Stack-based buffer overflow in Microsoft Office (CWE-121) enables local code execution across a broad range of affected builds including Office 2016, 2019, LTSC 2021, LTSC 2024, Office 365 for Mac, LTSC for Mac 2021/2024, and Microsoft 365 Apps for Enterprise. Exploitation requires user interaction - consistent with a maliciously crafted document delivery model - and achieves full confidentiality, integrity, and availability compromise within the Office process context. …
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 | User interaction is required - the target must actively open a specially crafted Microsoft Office document (CVSS UI:R). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 7.8 High score (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) captures the core tension of this vulnerability: the impact triad is maximal (full C/I/A compromise), but the delivery model is constrained to local file-based interaction, meaningfully limiting opportunistic mass exploitation compared to a fully remote no-click vector. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker sends a phishing email containing a specially crafted Office document to a target user. When the user opens the file, the malformed content triggers a stack-based buffer overflow in an Office parsing routine, overwriting the saved return address on the stack with a pointer to attacker-controlled data. … |
| Remediation | Apply the vendor-released patches as the primary remediation. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, inventory all instances of affected Office versions (Office 2016, 2019, LTSC 2021/2024, Office 365 for Mac, and Microsoft 365 Apps for Enterprise) across the organization. …
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-121 – Stack-based Buffer Overflow
View allSame technique Stack Overflow
View allShare
External POC / Exploit Code
Leaving vuln.today