CVE-2026-45463: CWE-191: Integer Underflow (Wrap or Wraparound) in Microsoft Microsoft 365 Apps for Enterprise
Integer underflow (wrap or wraparound) in Microsoft Office allows an unauthorized attacker to execute code locally.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-45463) is an integer underflow (CWE-191) in Microsoft 365 Apps for Enterprise, which can lead to local code execution by an unauthorized attacker. The issue arises from integer wrap or wraparound conditions in Microsoft Office components. The CVSS v3.1 score is 8.4, indicating high impact on confidentiality, integrity, and availability. Microsoft has published an official fix and manages remediation for this cloud-hosted service. No active exploitation has been reported.
Potential Impact
Successful exploitation allows an unauthorized attacker to execute code locally on affected Microsoft 365 Apps for Enterprise installations. This can lead to full compromise of the affected system's confidentiality, integrity, and availability. The vulnerability is rated high severity with a CVSS score of 8.4.
Mitigation Recommendations
An official fix is available from Microsoft. Since Microsoft 365 Apps for Enterprise is a cloud service, Microsoft manages the remediation process. Users and administrators should ensure that their Microsoft 365 Apps for Enterprise installations are updated according to Microsoft's guidance available at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45463.
CVE-2026-45463: CWE-191: Integer Underflow (Wrap or Wraparound) in Microsoft Microsoft 365 Apps for Enterprise
Description
Integer underflow (wrap or wraparound) in Microsoft Office allows an unauthorized attacker to execute code locally.
CVSS v3.1
Score 8.4high
Affected software
Microsoft
Microsoft 365 Apps for Enterprise
Microsoft
Microsoft Office 2016
Microsoft
Microsoft Office 2019
Microsoft
Microsoft Office 365 for Mac
Microsoft
Microsoft Office for Android
Microsoft
Microsoft Office LTSC 2021
Microsoft
Microsoft Office LTSC 2024
Microsoft
Microsoft Office LTSC for Mac 2021
Microsoft
Microsoft Office LTSC for Mac 2024
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-45463) is an integer underflow (CWE-191) in Microsoft 365 Apps for Enterprise, which can lead to local code execution by an unauthorized attacker. The issue arises from integer wrap or wraparound conditions in Microsoft Office components. The CVSS v3.1 score is 8.4, indicating high impact on confidentiality, integrity, and availability. Microsoft has published an official fix and manages remediation for this cloud-hosted service. No active exploitation has been reported.
Potential Impact
Successful exploitation allows an unauthorized attacker to execute code locally on affected Microsoft 365 Apps for Enterprise installations. This can lead to full compromise of the affected system's confidentiality, integrity, and availability. The vulnerability is rated high severity with a CVSS score of 8.4.
Mitigation Recommendations
An official fix is available from Microsoft. Since Microsoft 365 Apps for Enterprise is a cloud service, Microsoft manages the remediation process. Users and administrators should ensure that their Microsoft 365 Apps for Enterprise installations are updated according to Microsoft's guidance available at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45463.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-05-12T16:06:43.097Z
- 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-2026-45463","vendor":"Microsoft"}]
Threat ID: 6a284cd98dd33fbd85664c60
Added to database: 06/09/2026, 17:26:49 UTC
Last enriched: 08/14/2026, 13:34:31 UTC
Last updated: 09/11/2026, 07:31:53 UTC
Views: 98
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