CVE-2026-55131: 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-2026-55131) is a heap-based buffer overflow in Microsoft Office Excel component of Microsoft 365 Apps for Enterprise. It enables an unauthorized attacker to execute arbitrary code locally. The CVSS 3.1 base score is 7.8, indicating high severity with impact on confidentiality, integrity, and availability. The vulnerability affects version 16.0.1. Microsoft has released an official fix and manages remediation for this cloud-hosted service. No known active exploitation has been reported.
Potential Impact
Successful exploitation could allow an attacker to execute arbitrary code locally, potentially leading to full compromise of the affected system's confidentiality, integrity, and availability. However, there are no known exploits in the wild currently.
Mitigation Recommendations
An official fix is available from Microsoft. Since Microsoft 365 Apps for Enterprise is a cloud service, Microsoft manages the remediation server-side. Users and administrators should ensure their environments are updated according to Microsoft's guidance available at the vendor advisory URL: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55131.
CVE-2026-55131: 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-2026-55131) is a heap-based buffer overflow in Microsoft Office Excel component of Microsoft 365 Apps for Enterprise. It enables an unauthorized attacker to execute arbitrary code locally. The CVSS 3.1 base score is 7.8, indicating high severity with impact on confidentiality, integrity, and availability. The vulnerability affects version 16.0.1. Microsoft has released an official fix and manages remediation for this cloud-hosted service. No known active exploitation has been reported.
Potential Impact
Successful exploitation could allow an attacker to execute arbitrary code locally, potentially leading to full compromise of the affected system's confidentiality, integrity, and availability. However, there are no known exploits in the wild currently.
Mitigation Recommendations
An official fix is available from Microsoft. Since Microsoft 365 Apps for Enterprise is a cloud service, Microsoft manages the remediation server-side. Users and administrators should ensure their environments are updated according to Microsoft's guidance available at the vendor advisory URL: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55131.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-06-16T15:03:49.681Z
- 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-2026-55131","vendor":"Microsoft"}]
Threat ID: 6a5676b668715ace43f0ab77
Added to database: 07/14/2026, 17:49:42 UTC
Last enriched: 07/14/2026, 19:05:19 UTC
Last updated: 07/15/2026, 01:19:16 UTC
Views: 4
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