CVE-2026-20950 Details
Description
Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
A use-after-free vulnerability has been identified in Microsoft Office Excel. This issue allows an unauthorized attacker to execute code locally on the affected system. The vulnerability arises from improper memory management, which can be exploited under certain conditions.
Users can apply the security update provided by Microsoft to address this vulnerability. Instructions for downloading the security update are available on the Microsoft Update Catalog. For Microsoft Office LTSC for Mac 2021 and 2024, the security update can be downloaded via the Microsoft Update Catalog. For Microsoft 365 Apps for Enterprise, the security update is also available through the Microsoft Update Catalog. Office Online Server users can download the security update from the Microsoft Download Center.
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 Jan 14, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20950 | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-416 | Use After Free | [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 | < 16.0.10417.20083 |
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 |
| Jan 14, 2026 | Initial Analysis | [email protected] |
| Jan 13, 2026 | New CVE Received | [email protected] |