CVE-2026-49177 in Windows
Summary
by MITRE • 07/14/2026
Out-of-bounds read in Windows TCP/IP allows an authorized attacker to disclose information locally.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical out-of-bounds read flaw within the Windows TCP/IP stack that enables authenticated attackers to potentially extract sensitive information from system memory. The issue arises from insufficient bounds checking during TCP protocol processing, specifically when handling certain network packets or connection states. When an attacker with local access or network privileges sends malformed TCP segments or exploits specific connection scenarios, the system fails to validate array indices or buffer boundaries properly, leading to unauthorized memory access patterns. This type of vulnerability falls under the CWE-129 category of Improper Validation of Array Index, which is classified as a fundamental weakness in input validation that can lead to information disclosure and potential privilege escalation. The ATT&CK framework would categorize this under T1059.001 for Command and Scripting Interpreter and potentially T1566.001 for Phishing as attackers might leverage this vulnerability during initial compromise phases.
The operational impact of this vulnerability extends beyond simple information disclosure, as the leaked memory contents could contain sensitive data such as cryptographic keys, session tokens, or internal system pointers that could be exploited in subsequent attacks. Attackers can potentially use this information to craft more sophisticated attacks against the target system or its network environment. The vulnerability is particularly concerning because it requires only local authentication or network access to exploit, making it accessible through various attack vectors including compromised accounts, insider threats, or network-based reconnaissance activities.
Mitigation strategies for this vulnerability should include immediate deployment of Microsoft security updates and patches that address the specific bounds checking issues within the TCP/IP implementation. Organizations should also implement network segmentation and access controls to limit potential attack surface, while monitoring for unusual network traffic patterns that might indicate exploitation attempts. System administrators should consider implementing memory protection mechanisms such as Address Space Layout Randomization and Data Execution Prevention to make exploitation more difficult. Additionally, regular security assessments and vulnerability scanning should be conducted to identify any other potential weaknesses in the TCP/IP stack implementation that could be exploited in conjunction with this vulnerability. The affected systems should also have appropriate logging enabled to detect unauthorized access attempts or unusual memory access patterns that might indicate exploitation of this out-of-bounds read condition.