CVE-2026-50307 in Windows
Summary
by MITRE • 07/14/2026
Use after free in Windows TCP/IP allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical use-after-free condition within the Windows TCP/IP stack that enables local privilege escalation for authenticated attackers. The flaw occurs when the system fails to properly validate memory references during network protocol processing, specifically affecting how the tcpip.sys kernel driver handles certain network operations. When an attacker crafts malicious network traffic or manipulates existing connections, they can trigger a scenario where freed memory locations are accessed after being reallocated, creating opportunities for arbitrary code execution and privilege elevation.
The technical implementation of this vulnerability stems from inadequate input validation and memory management within the Windows networking subsystem. During TCP/IP protocol processing, particularly when handling specific packet structures or connection states, the kernel driver does not properly verify that referenced memory regions remain valid before accessing them. This use-after-free condition can be exploited through carefully constructed network traffic that forces the system to execute code in kernel space with elevated privileges. The vulnerability affects Windows operating systems including windows 10, windows server 2016, and windows server 2019, making it particularly dangerous in enterprise environments where local access might be gained through legitimate user accounts.
The operational impact of this vulnerability extends beyond simple privilege escalation to potentially enable full system compromise. An attacker with local access can leverage this condition to elevate their privileges from standard user level to SYSTEM level, providing complete control over the affected system. This makes the vulnerability particularly attractive for attackers who may have already gained initial access through other means such as phishing or credential theft. The exploitation typically requires minimal network access and can be performed without requiring additional attack vectors, making it a preferred target for adversaries seeking persistent access to compromised systems.
Mitigation strategies should prioritize immediate patch deployment from Microsoft as the primary defense mechanism. Organizations must ensure that all affected Windows systems receive security updates promptly, particularly those running server operating systems where network access might be more prevalent. Network segmentation and access controls should be implemented to limit local user privileges and reduce the attack surface for potential exploitation. Monitoring for unusual network traffic patterns or kernel-level activity can help detect exploitation attempts, while maintaining current antivirus signatures and endpoint detection tools provides additional layers of protection against known exploit techniques.
This vulnerability aligns with several cybersecurity frameworks including CWE-416 which specifically addresses use-after-free conditions in memory management. The attack pattern follows established methods described in the MITRE ATT&CK framework under privilege escalation techniques, particularly those involving kernel exploits and local privilege escalation. Organizations should also consider implementing the principle of least privilege and regular security assessments to identify and remediate similar vulnerabilities before they can be exploited by malicious actors.