CVE-2026-40363: CWE-122: Heap-based Buffer Overflow in Microsoft Microsoft 365 Apps for Enterprise
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
AI Analysis
Technical Summary
This vulnerability is a heap-based buffer overflow (CWE-122) in Microsoft 365 Apps for Enterprise (version 16.0.1). It permits an unauthorized attacker to execute code locally on the affected system. The CVSS 3.1 score is 8.4, indicating high impact on confidentiality, integrity, and availability. Microsoft has published an official fix and manages remediation for this cloud service. No known active exploitation has been reported.
Potential Impact
Successful exploitation allows local code execution by an unauthorized attacker, potentially leading to full compromise of the affected system's confidentiality, integrity, and availability.
Mitigation Recommendations
An official fix is available from Microsoft. Since this is a cloud-hosted service, Microsoft manages remediation server-side. Users and administrators should ensure their Microsoft 365 Apps for Enterprise environment is updated according to Microsoft's guidance in the vendor advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40363.
CVE-2026-40363: CWE-122: Heap-based Buffer Overflow in Microsoft Microsoft 365 Apps for Enterprise
Description
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
CVSS v3.1
Score 8.4high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability is a heap-based buffer overflow (CWE-122) in Microsoft 365 Apps for Enterprise (version 16.0.1). It permits an unauthorized attacker to execute code locally on the affected system. The CVSS 3.1 score is 8.4, indicating high impact on confidentiality, integrity, and availability. Microsoft has published an official fix and manages remediation for this cloud service. No known active exploitation has been reported.
Potential Impact
Successful exploitation allows local code execution by an unauthorized attacker, potentially leading to full compromise of the affected system's confidentiality, integrity, and availability.
Mitigation Recommendations
An official fix is available from Microsoft. Since this is a cloud-hosted service, Microsoft manages remediation server-side. Users and administrators should ensure their Microsoft 365 Apps for Enterprise environment is updated according to Microsoft's guidance in the vendor advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40363.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-04-11T23:06:15.614Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Is Cloud Service
- true
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40363","vendor":"Microsoft"}]
Threat ID: 6a036550cbff5d861008c8ec
Added to database: 05/12/2026, 17:37:20 UTC
Last enriched: 06/19/2026, 17:36:33 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 60
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