CVE-2026-81398: CWE-122: Heap-based Buffer Overflow in Microsoft Microsoft 365 Apps for Enterprise
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-81398) involves a heap-based buffer overflow in Microsoft Office Excel, part of Microsoft 365 Apps for Enterprise. It enables unauthorized local code execution. The CVSS 3.1 score is 7.8, indicating high impact on confidentiality, integrity, and availability. The affected version is exactly 16.0.1. Microsoft has released an official fix and manages remediation for this cloud service. No active exploitation has been reported.
Potential Impact
Successful exploitation allows an unauthorized attacker to execute code locally on the affected system, potentially leading to full compromise of confidentiality, integrity, and availability of the affected application environment.
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 apply the official update as directed in the Microsoft security advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-81398 to mitigate this vulnerability.
CVE-2026-81398: CWE-122: Heap-based Buffer Overflow in Microsoft Microsoft 365 Apps for Enterprise
Description
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
CVSS v3.1
Score 7.8high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-81398) involves a heap-based buffer overflow in Microsoft Office Excel, part of Microsoft 365 Apps for Enterprise. It enables unauthorized local code execution. The CVSS 3.1 score is 7.8, indicating high impact on confidentiality, integrity, and availability. The affected version is exactly 16.0.1. Microsoft has released an official fix and manages remediation for this cloud service. No active exploitation has been reported.
Potential Impact
Successful exploitation allows an unauthorized attacker to execute code locally on the affected system, potentially leading to full compromise of confidentiality, integrity, and availability of the affected application environment.
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 apply the official update as directed in the Microsoft security advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-81398 to mitigate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-08-26T18:46:26.215Z
- 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-2026-81398","vendor":"Microsoft"}]
Threat ID: 6aa04571acd9273b49fb5fa3
Added to database: 09/08/2026, 17:27:13 UTC
Last enriched: 09/08/2026, 18:22:09 UTC
Last updated: 09/08/2026, 23:53:30 UTC
Views: 3
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