CVE-2026-55122: 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
CVE-2026-55122 is a CWE-125 out-of-bounds read vulnerability in Microsoft Office Excel as part of Microsoft 365 Apps for Enterprise. This vulnerability enables an unauthorized attacker to read memory outside the intended bounds, potentially disclosing sensitive information locally. The vulnerability affects version 16.0.1. Microsoft has published an official fix and manages remediation for this cloud service. No known exploits are reported in the wild at this time.
Potential Impact
The vulnerability allows unauthorized local information disclosure due to an out-of-bounds read in Excel. The CVSS 3.1 score of 7.1 reflects high confidentiality impact and high availability impact, with no integrity impact. There is no indication of remote exploitation without user interaction, and no known active exploitation has been reported.
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 as per Microsoft's advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55122.
CVE-2026-55122: 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 7.1high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-55122 is a CWE-125 out-of-bounds read vulnerability in Microsoft Office Excel as part of Microsoft 365 Apps for Enterprise. This vulnerability enables an unauthorized attacker to read memory outside the intended bounds, potentially disclosing sensitive information locally. The vulnerability affects version 16.0.1. Microsoft has published an official fix and manages remediation for this cloud service. No known exploits are reported in the wild at this time.
Potential Impact
The vulnerability allows unauthorized local information disclosure due to an out-of-bounds read in Excel. The CVSS 3.1 score of 7.1 reflects high confidentiality impact and high availability impact, with no integrity impact. There is no indication of remote exploitation without user interaction, and no known active exploitation has been reported.
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 as per Microsoft's advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55122.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-06-16T15:03:49.680Z
- 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-2026-55122","vendor":"Microsoft"}]
Threat ID: 6a5676b568715ace43f0ab04
Added to database: 07/14/2026, 17:49:41 UTC
Last enriched: 08/13/2026, 15:38:14 UTC
Last updated: 08/27/2026, 22:52:12 UTC
Views: 57
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