CVE-2026-70318: CWE-20: Improper Input Validation in Microsoft Microsoft 365 Apps for Enterprise
Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-70318) in Microsoft Office Excel within Microsoft 365 Apps for Enterprise is caused by improper input validation. It allows an unauthorized attacker with local access to disclose information. The CVSS 3.1 vector indicates local attack vector, low complexity, no privileges required, user interaction required, unchanged scope, high confidentiality impact, no integrity or availability impact. The vendor has released an official fix and manages remediation for this cloud service.
Potential Impact
An unauthorized attacker with local access and requiring user interaction could exploit this vulnerability to disclose sensitive information. There is no impact on integrity or availability. The confidentiality impact is high, meaning sensitive data could be exposed.
Mitigation Recommendations
An official fix is available from Microsoft. Since this is a cloud-hosted service, Microsoft manages the remediation server-side. Users and administrators should ensure their Microsoft 365 Apps for Enterprise are updated to the fixed version or later as per the vendor advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70318.
CVE-2026-70318: CWE-20: Improper Input Validation in Microsoft Microsoft 365 Apps for Enterprise
Description
Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
CVSS v3.1
Score 5.5medium
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-70318) in Microsoft Office Excel within Microsoft 365 Apps for Enterprise is caused by improper input validation. It allows an unauthorized attacker with local access to disclose information. The CVSS 3.1 vector indicates local attack vector, low complexity, no privileges required, user interaction required, unchanged scope, high confidentiality impact, no integrity or availability impact. The vendor has released an official fix and manages remediation for this cloud service.
Potential Impact
An unauthorized attacker with local access and requiring user interaction could exploit this vulnerability to disclose sensitive information. There is no impact on integrity or availability. The confidentiality impact is high, meaning sensitive data could be exposed.
Mitigation Recommendations
An official fix is available from Microsoft. Since this is a cloud-hosted service, Microsoft manages the remediation server-side. Users and administrators should ensure their Microsoft 365 Apps for Enterprise are updated to the fixed version or later as per the vendor advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70318.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-08-04T00:01:20.933Z
- 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-2026-70318","vendor":"Microsoft"}]
Threat ID: 6a7b583ebf8831d539156793
Added to database: 08/11/2026, 17:13:34 UTC
Last enriched: 08/11/2026, 17:43:06 UTC
Last updated: 08/12/2026, 00:12:10 UTC
Views: 2
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