CVE-2026-49177 Windows TCP/IP Information Disclosure Vulnerability

Api.Msrc.Microsoft • August 31, 2026

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Released: Jul 14, 2026

Last updated: Aug 31, 2026

Please see Common Vulnerability Scoring System for more information on the definition of these metrics.

Out-of-bounds read in Windows TCP/IP allows an authorized attacker to disclose information locally.

The following table provides an exploitability assessment for this vulnerability at the time of original publication.

uhg and Tay Kiat Loong

Kentaro Kawane with GMO Cybersecurity by Ierae, Inc.

KPC of Cisco Talos with Cisco Talos

Microsoft Red Team (MRT) with Microsoft

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Updated an acknowledgement. This is an informational change only.

Information published.

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This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.

Multiple CVEs Disclosed for Windows Vulnerabilities On August 31, 2026, multiple vulnerabilities affecting Windows systems were disclosed, including CVE-2026-26174, CVE-2026-49177, and others. These vulnerabilities include heap-based buffer overflows and improper authorization issues that allow unauthorized attackers to execute code locally or elevate privileges. Specifically, CVE-2026-26174 involves a race condition in Windows Server Update Service, enabling privilege escalation. CVE-2026-49177 is an out-of-bounds read in Windows TCP/IP that allows information disclosure. The vulnerabilities affect various Windows components, including Microsoft Office and Remote Desktop Client. User interaction is often required for exploitation, as attackers must convince users to open malicious files. As of now, some vulnerabilities are being actively exploited, raising concerns about their impact on organizations relying on affected systems. 64 sources 70

Extracted Entities

CVE-2026-49177 Windows TCP/IP Information Disclosure Vulnerability

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Extracted Entities

Attack Types (1)

CVEs (1)

CWE Weaknesses (1)

Platforms (1)