CVE-2026-55138: CWE-822: Untrusted Pointer Dereference in Microsoft Microsoft 365 Apps for Enterprise
Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
AI Analysis
Technical Summary
This vulnerability involves an untrusted pointer dereference in Microsoft Office Excel within Microsoft 365 Apps for Enterprise. It allows an unauthorized attacker with local access to disclose information. The CVSS 3.1 vector indicates low attack complexity, no privileges required, user interaction required, and high confidentiality impact without integrity or availability impact. The vendor has released an official fix and manages remediation for this cloud-hosted service.
Potential Impact
An unauthorized local attacker can 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 locally.
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 Microsoft 365 Apps for Enterprise installations are updated according to Microsoft's guidance at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55138.
CVE-2026-55138: CWE-822: Untrusted Pointer Dereference in Microsoft Microsoft 365 Apps for Enterprise
Description
Untrusted pointer dereference 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 involves an untrusted pointer dereference in Microsoft Office Excel within Microsoft 365 Apps for Enterprise. It allows an unauthorized attacker with local access to disclose information. The CVSS 3.1 vector indicates low attack complexity, no privileges required, user interaction required, and high confidentiality impact without integrity or availability impact. The vendor has released an official fix and manages remediation for this cloud-hosted service.
Potential Impact
An unauthorized local attacker can 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 locally.
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 Microsoft 365 Apps for Enterprise installations are updated according to Microsoft's guidance at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55138.
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-2026-55138","vendor":"Microsoft"}]
Threat ID: 6a5676b868715ace43f0ab96
Added to database: 07/14/2026, 17:49:44 UTC
Last enriched: 07/14/2026, 19:04:23 UTC
Last updated: 07/15/2026, 00:47:36 UTC
Views: 2
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