CVE-2026-40360 Details
Description
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
A vulnerability allowing out-of-bounds read has been identified in Microsoft Office Excel. This issue could enable an unauthorized attacker to locally disclose information by reading small portions of heap memory. The vulnerability affects multiple versions of Excel, including Excel 2016 (both 32-bit and 64-bit editions), Office LTSC for Mac 2024, Office LTSC 2024 for 32-bit and 64-bit editions, Office LTSC 2021 for 32-bit and 64-bit editions, Office LTSC for Mac 2021, Microsoft 365 Apps for Enterprise for 32-bit and 64-bit systems, Office 2019 for 32-bit and 64-bit editions, and Office Online Server.
Users can download the security update for Microsoft Excel 2016 (32-bit and 64-bit editions) from the Microsoft Update Catalog. For Microsoft Office LTSC for Mac 2024, the security update is available through the Mac App Store. Office LTSC 2024 for 32-bit and 64-bit editions also has a security update available. Microsoft 365 Apps for Enterprise users can download the security update from the Microsoft Update Catalog. For Office 2019, the security update is available through the Microsoft Update Catalog. Office Online Server users can download the security update from the Microsoft Update Catalog.
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 May 13, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40360 | [email protected] | Vendor 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 excel | 2016 |
CPE
Remediation
| |
| microsoft office | 2019 |
CPE
Remediation
| |
| microsoft office long term servicing channel | 2021 2024 |
CPE
Remediation
| |
| microsoft office online server | < 16.0.10417.20128 |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 19, 2026 | Initial Analysis | [email protected] |
| May 12, 2026 | New CVE Received | [email protected] |