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) involves a heap-based buffer overflow in Microsoft Office Excel, part of Microsoft 365 Apps for Enterprise. It enables an unauthorized attacker to execute arbitrary code locally. The vulnerability has been assigned a CVSS v3.1 score of 7.8, indicating high severity. Microsoft has published an official fix and manages remediation for this cloud service. The affected version explicitly includes version 16.0.1. No active exploitation has been reported.
Potential Impact
Successful exploitation of this vulnerability could allow an unauthorized attacker to execute arbitrary code locally, potentially leading to full compromise of the affected application and associated user privileges. The impact includes high confidentiality, integrity, and availability consequences as indicated by the CVSS vector.
Mitigation Recommendations
An official fix is available from Microsoft. Since this is a cloud-hosted service, Microsoft manages the remediation on the server side. Users and administrators should consult the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55131 for detailed patching and update instructions to ensure the vulnerability is mitigated.
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) involves a heap-based buffer overflow in Microsoft Office Excel, part of Microsoft 365 Apps for Enterprise. It enables an unauthorized attacker to execute arbitrary code locally. The vulnerability has been assigned a CVSS v3.1 score of 7.8, indicating high severity. Microsoft has published an official fix and manages remediation for this cloud service. The affected version explicitly includes version 16.0.1. No active exploitation has been reported.
Potential Impact
Successful exploitation of this vulnerability could allow an unauthorized attacker to execute arbitrary code locally, potentially leading to full compromise of the affected application and associated user privileges. The impact includes high confidentiality, integrity, and availability consequences as indicated by the CVSS vector.
Mitigation Recommendations
An official fix is available from Microsoft. Since this is a cloud-hosted service, Microsoft manages the remediation on the server side. Users and administrators should consult the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55131 for detailed patching and update instructions to ensure the vulnerability is mitigated.
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: 08/13/2026, 15:40:14 UTC
Last updated: 08/27/2026, 22:52:12 UTC
Views: 90
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