CVE-2026-55140: 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 (CVE-2026-55140) involves a heap-based buffer overflow in Microsoft 365 Apps for Enterprise version 16.0.1. It enables an unauthorized attacker to execute code locally by exploiting improper memory management. The CVSS 3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability. Microsoft has released an official fix and manages remediation for this cloud-hosted service. No active exploitation has been reported.
Potential Impact
Successful exploitation could allow an unauthorized attacker to execute arbitrary code locally, potentially leading to full compromise of the affected application and system. The vulnerability impacts confidentiality, integrity, and availability at a high level. No known exploits are currently active in the wild.
Mitigation Recommendations
An official fix is available from Microsoft. Since this is a cloud-hosted service, Microsoft manages remediation server-side. Users should apply the official update as directed in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55140 to mitigate this vulnerability.
CVE-2026-55140: 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 7.8high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-55140) involves a heap-based buffer overflow in Microsoft 365 Apps for Enterprise version 16.0.1. It enables an unauthorized attacker to execute code locally by exploiting improper memory management. The CVSS 3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability. Microsoft has released an official fix and manages remediation for this cloud-hosted service. No active exploitation has been reported.
Potential Impact
Successful exploitation could allow an unauthorized attacker to execute arbitrary code locally, potentially leading to full compromise of the affected application and system. The vulnerability impacts confidentiality, integrity, and availability at a high level. No known exploits are currently active in the wild.
Mitigation Recommendations
An official fix is available from Microsoft. Since this is a cloud-hosted service, Microsoft manages remediation server-side. Users should apply the official update as directed in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55140 to mitigate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-06-16T15:03:49.682Z
- 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-2026-55140","vendor":"Microsoft"}]
Threat ID: 6a5676b868715ace43f0ab9c
Added to database: 07/14/2026, 17:49:44 UTC
Last enriched: 08/13/2026, 15:42:08 UTC
Last updated: 08/28/2026, 22:52:12 UTC
Views: 46
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