CVE-2026-58618 Details
Description
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
A heap-based buffer overflow vulnerability has been identified in Microsoft Office Excel. This vulnerability allows an unauthorized attacker to execute code locally. It affects multiple versions of Excel, including Excel 2016 (both 32-bit and 64-bit editions), Excel LTSC 2021 (32-bit and 64-bit editions), Excel LTSC for Mac 2021, Excel LTSC for Mac 2024, and Office Online Server. The vulnerability arises from a heap-based buffer overflow, which can be exploited by sending a malicious Office file to a user and convincing them to open it.
Users can download the security update for this vulnerability through the Microsoft Update Catalog. For Office 365 for Mac, the update is available via the Mac App Store. Instructions for updating can be found in the release notes on the Microsoft 365 for Mac page.
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 10, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58618 | [email protected] | PatchVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-122 | Heap-based Buffer Overflow | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| microsoft 365 apps | All versions |
CPE
Remediation
| |
| microsoft excel | 2016 |
CPE
Remediation
| |
| microsoft microsoft 365 | 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 office online server | < 16.0.10417.20175 |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 16, 2026 | Initial Analysis | [email protected] |
| Jul 15, 2026 | CVE Modified | CISA-ADP |
| Jul 14, 2026 | CVE Modified | CISA-ADP |
| Jul 14, 2026 | New CVE Received | [email protected] |