CVE-2026-50387 in Windows
Summary
by MITRE • 07/14/2026
Stack-based buffer overflow in Windows GDI allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 07/14/2026
A stack-based buffer overflow vulnerability exists within the Windows Graphics Device Interface GDI component that enables authenticated attackers to achieve local privilege escalation. This flaw resides in how the system handles certain graphics operations and memory management within the kernel-mode drivers responsible for rendering graphical elements. The vulnerability is classified as a classic stack corruption issue where insufficient bounds checking allows an attacker to overwrite adjacent memory locations on the call stack. When a malicious user with standard account privileges executes crafted graphics commands or renders specially constructed graphical content, the vulnerable code path can be triggered to overwrite return addresses and potentially execute arbitrary code with kernel-level privileges.
The technical implementation of this vulnerability demonstrates characteristics consistent with CWE-121 Stack-based Buffer Overflow, where insufficient control over buffer boundaries leads to memory corruption in stack memory regions. The attack vector requires local system access and leverages the inherent trust relationships within Windows graphical subsystems. The GDI component operates at kernel level and processes graphics rendering requests from user-mode applications, making it an attractive target for privilege escalation attacks. When exploited successfully, this vulnerability allows an attacker to bypass standard security mechanisms including user access control, integrity checks, and privilege validation routines that normally protect system resources.
The operational impact of this vulnerability extends beyond simple local privilege escalation as it can enable attackers to establish persistent access to compromised systems. Once elevated to kernel mode privileges, malicious actors can manipulate system memory, modify critical registry entries, install rootkits, and bypass endpoint protection mechanisms. The vulnerability affects multiple Windows versions including windows 10, windows server 2016, and later releases where the affected GDI drivers remain active in the kernel space. Attackers typically leverage this vulnerability through malware that triggers the graphics rendering path or through legitimate applications that may be compromised by supply chain attacks targeting graphics libraries.
Mitigation strategies should focus on immediate patching of affected Windows versions and implementing additional security controls to limit attack surface exposure. Microsoft has released security updates addressing this specific vulnerability through regular security patches, requiring administrators to apply these updates promptly across all systems. Additional defensive measures include enabling kernel mode exploit protection features such as driver signature enforcement, controlling access to graphics rendering APIs, and monitoring for suspicious graphics-related system calls. Network segmentation and least privilege principles should be enforced to limit lateral movement capabilities once a system is compromised. Organizations should also implement continuous monitoring solutions capable of detecting anomalous behavior in kernel-mode operations and establish incident response procedures specifically designed to handle kernel-level privilege escalation attacks. This vulnerability aligns with ATT&CK technique T1068 for Local Privilege Escalation and T1547 for Registry Run Keys/Startup Folder, demonstrating the multi-faceted nature of exploitation approaches that security teams must consider when defending against such threats.