CVE-2026-55898: CWE-125: Out-of-bounds Read in Microsoft Microsoft 365 Apps for Enterprise
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-55898) involves an out-of-bounds read (CWE-125) in Microsoft Office Excel as part of Microsoft 365 Apps for Enterprise. The flaw enables an unauthorized attacker to perform a local information disclosure. The CVSS 3.1 vector indicates the attack requires local access with low complexity, no privileges, and user interaction. Confidentiality impact is low, integrity is not affected, and availability impact is high. Microsoft has published an official fix and manages remediation for this cloud-hosted service.
Potential Impact
An attacker with local access and user interaction can exploit this vulnerability to read memory outside the intended bounds, potentially disclosing sensitive information. The impact on confidentiality is low, integrity is unaffected, and availability impact is high. There are no known exploits in the wild at this time.
Mitigation Recommendations
Microsoft has released an official fix for this vulnerability. Since this is a cloud-hosted service, Microsoft manages remediation server-side. Users should ensure their Microsoft 365 Apps for Enterprise are updated to the fixed version as per Microsoft's advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55898.
CVE-2026-55898: CWE-125: Out-of-bounds Read in Microsoft Microsoft 365 Apps for Enterprise
Description
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
CVSS v3.1
Score 6.1medium
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-55898) involves an out-of-bounds read (CWE-125) in Microsoft Office Excel as part of Microsoft 365 Apps for Enterprise. The flaw enables an unauthorized attacker to perform a local information disclosure. The CVSS 3.1 vector indicates the attack requires local access with low complexity, no privileges, and user interaction. Confidentiality impact is low, integrity is not affected, and availability impact is high. Microsoft has published an official fix and manages remediation for this cloud-hosted service.
Potential Impact
An attacker with local access and user interaction can exploit this vulnerability to read memory outside the intended bounds, potentially disclosing sensitive information. The impact on confidentiality is low, integrity is unaffected, and availability impact is high. There are no known exploits in the wild at this time.
Mitigation Recommendations
Microsoft has released an official fix for this vulnerability. Since this is a cloud-hosted service, Microsoft manages remediation server-side. Users should ensure their Microsoft 365 Apps for Enterprise are updated to the fixed version as per Microsoft's advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55898.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-06-17T17:36:34.621Z
- 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-2026-55898","vendor":"Microsoft"}]
Threat ID: 6a5676b868715ace43f0aba8
Added to database: 07/14/2026, 17:49:44 UTC
Last enriched: 08/13/2026, 15:43:15 UTC
Last updated: 08/28/2026, 11:04:20 UTC
Views: 68
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