CVE-2026-54131

Analyzed Analyzed - Analysis Complete

Use After Free in Microsoft Office Excel Allows Code Execution

Publication date: 2026-07-14

Last updated on: 2026-07-15

Assigner: Microsoft Corporation

Description

Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-07-14

Last Modified

2026-07-15

Generated

2026-08-03

AI Q&A

2026-07-15

EPSS Evaluated

2026-08-02

NVD

CVE-2026-54131

EUVD

EUVD-2026-44227

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	365_apps	*
microsoft	365_apps	*
microsoft	office_2019	*
microsoft	office_2019	*
microsoft	microsoft_365	*
microsoft	office_2021	*
microsoft	office_2021	*
microsoft	office_2021	*
microsoft	office_2024	*
microsoft	office_2024	*
microsoft	office_2024	*
microsoft	office_online_server	to 16.0.10417.20175 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-416	The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

Executive Summary

This is a use-after-free vulnerability in Microsoft Office Excel. It allows an unauthorized attacker to execute arbitrary code on a vulnerable system by exploiting a memory management flaw.

Detection Guidance

Detection of this vulnerability requires monitoring for unusual activity in Microsoft Office Excel processes. Check for crashes or unexpected behavior in Excel files. Use Microsoft Defender for Endpoint to scan for indicators of compromise. Review system logs for Excel-related errors or memory corruption events.

Impact Analysis

An attacker could exploit this to run malicious code on your computer, potentially stealing data, installing malware, or taking control of your system. Opening a specially crafted Excel file could trigger the exploit.

Compliance Impact

This vulnerability allows unauthorized code execution, which could lead to unauthorized data access or modification. For GDPR, this may result in data breaches requiring notification under Article 33. For HIPAA, it could compromise protected health information integrity or confidentiality.

Mitigation Strategies

Apply the latest security updates from Microsoft for Office Excel as soon as possible to patch the use-after-free vulnerability.

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