CVE-2026-62889

Analyzed Analyzed - Analysis Complete

Double Free in Windows SSTP Allows Remote Code Execution

Publication date: 2026-08-11

Last updated on: 2026-08-16

Assigner: Microsoft Corporation

Description

Double free in Windows Secure Socket Tunneling Protocol (SSTP) allows an unauthorized attacker to execute code over a network.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-11

Last Modified

2026-08-16

Generated

2026-09-01

AI Q&A

2026-08-12

EPSS Evaluated

2026-08-30

NVD

CVE-2026-62889

EUVD

EUVD-2026-56401

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2012	r2
microsoft	windows_server_2012	*
microsoft	windows_10_1607	to 10.0.14393.9418 (exc)
microsoft	windows_10_1607	to 10.0.14393.9418 (exc)
microsoft	windows_10_1809	to 10.0.17763.9115 (exc)
microsoft	windows_10_1809	to 10.0.17763.9115 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7517 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7517 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9106 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9106 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2704 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2704 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9106 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9106 (exc)
microsoft	windows_server_2016	to 10.0.14393.9418 (exc)
microsoft	windows_server_2019	to 10.0.17763.9115 (exc)
microsoft	windows_server_2022	to 10.0.20348.5440 (exc)
microsoft	windows_server_2025	to 10.0.26100.33222 (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 the Windows Secure Socket Tunneling Protocol (SSTP). A double free occurs when a program frees the same memory block twice, which can lead to memory corruption and allow an attacker to execute arbitrary code remotely over a network.

Detection Guidance

Detection of CVE-2026-62889 requires monitoring for unusual activity in the Windows Secure Socket Tunneling Protocol (SSTP). Check for unexpected crashes or memory corruption in SSTP services. Review network traffic for anomalies related to SSTP connections. Ensure all Windows systems are updated with the latest security patches from Microsoft.

Impact Analysis

An attacker could exploit this flaw to run malicious code on your system remotely without needing authentication. This could lead to unauthorized access, data theft, or further compromise of your system or network.

Compliance Impact

This vulnerability allows remote code execution via a double free in SSTP, which could lead to unauthorized access or data breaches. Such incidents may violate compliance requirements under GDPR (data protection) and HIPAA (health data security) by exposing sensitive information or failing to maintain system integrity.

Mitigation Strategies

Apply the latest security updates from Microsoft to patch the SSTP double free vulnerability. Monitor Microsoft's advisory for patches and disable SSTP if not required until patched.

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