CVE-2026-55121 Details
Description
Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.
A vulnerability allowing out-of-bounds read has been identified in Microsoft Office. This issue could enable an unauthorized attacker to locally disclose information by accessing limited sensitive data from system memory. The vulnerability affects several different versions and products within the Microsoft Office suite, including Microsoft Office 2019, Microsoft 365 Apps for Enterprise, SharePoint Server 2019, and various editions of Office for Mac.
Users can download the security update for this vulnerability through the Microsoft Update Catalog. Specific download links are available in the Microsoft Office Security Update Release Notes.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jul 14, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55121 | [email protected] | PatchVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-125 | Out-of-bounds Read | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| microsoft 365 apps | All versions |
CPE
Remediation
| |
| microsoft microsoft 365 | All versions |
CPE
Remediation
| |
| microsoft office 2016 | All versions |
CPE
Remediation
| |
| microsoft office 2019 | All versions |
CPE
Remediation
| |
| microsoft office 2021 | All versions |
CPE
Remediation
| |
| microsoft office 2024 | All versions |
CPE
Remediation
| |
| microsoft sharepoint server | < 16.0.19725.20434 2016 2019 |
CPE
Remediation
| |
Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 15, 2026 | Reanalysis | [email protected] |
| Jul 15, 2026 | Reanalysis | [email protected] |
| Jul 15, 2026 | Initial Analysis | [email protected] |
| Jul 14, 2026 | New CVE Received | [email protected] |
| Jul 14, 2026 | CVE Modified | CISA-ADP |