Double Free in Windows Failover Cluster Elevates Privileges

Publication date: 2026-09-08

Last updated on: 2026-09-24

Assigner: Microsoft Corporation

Description

Double free in Windows Failover Cluster allows an authorized attacker to elevate privileges locally.

CVSS Scores

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Meta Information

Published

2026-09-08

Last Modified

2026-09-24

Generated

2026-09-29

AI Q&A

2026-09-10

EPSS Evaluated

2026-09-27

NVD

CVE-2026-71338

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2012	r2
microsoft	windows_server_2012	*
microsoft	windows_server_2025	to 10.0.26100.33438 (exc)
microsoft	windows_10_1607	to 10.0.14393.9512 (exc)
microsoft	windows_10_1607	to 10.0.14393.9512 (exc)
microsoft	windows_10_1809	to 10.0.17763.9245 (exc)
microsoft	windows_10_1809	to 10.0.17763.9245 (exc)
microsoft	windows_server_2016	to 10.0.14393.9512 (exc)
microsoft	windows_server_2019	to 10.0.17763.9245 (exc)
microsoft	windows_server_2022	to 10.0.20348.5622 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-415	The product calls free() twice on the same memory address.

Attack-Flow Graph

Executive Summary

This vulnerability is a double free issue in Windows Failover Cluster. A double free occurs when a program frees the same memory block twice, which can lead to memory corruption and potentially allow an attacker to execute arbitrary code or elevate privileges.

Impact Analysis

An authorized attacker could exploit this to elevate their privileges locally on a system running Windows Failover Cluster. This could allow them to gain higher-level access, potentially leading to unauthorized actions or control over the affected system.

Mitigation Strategies

Apply the latest security updates from Microsoft for Windows Failover Cluster to address the double free vulnerability.

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