CVE-2026-62746 in Windows
Summary
by MITRE • 08/11/2026
Buffer over-read in Windows Win32K allows an authorized attacker to disclose information locally.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability exists within the Windows Win32K subsystem which handles user-mode graphics operations and window management functions critical to the operating system's graphical interface. The buffer over-read occurs when the system processes certain graphics-related API calls without proper bounds checking on input data structures, allowing an attacker with valid user credentials to potentially read memory locations beyond allocated buffers. This type of vulnerability falls under CWE-125 which specifically addresses out-of-bounds read conditions that can lead to information disclosure and potentially more severe exploitation vectors.
The technical flaw manifests in the Win32K kernel-mode component where graphics rendering operations fail to validate the size or content of incoming data structures before processing them. When an authenticated user executes malicious code through crafted graphics API calls, the system's memory management routines can be tricked into reading beyond the intended buffer boundaries, potentially exposing sensitive kernel memory contents including credentials, encryption keys, or other confidential information. This vulnerability represents a classic example of how user-mode operations can escalate to kernel-level information disclosure when proper input validation is missing.
Operationally, this vulnerability creates a significant risk for local attackers who already possess valid user accounts on the target system. The information disclosure could reveal sensitive data such as memory addresses, kernel structures, or credential material that could be leveraged for further exploitation including privilege escalation attacks or lateral movement within the network. Attackers might use this information to bypass security controls like address space layout randomization or to craft more sophisticated exploits targeting other components of the Windows operating system.
Mitigation strategies should focus on implementing proper input validation and bounds checking throughout the Win32K subsystem, ensuring that all graphics-related API calls properly validate data structures before processing. Microsoft typically addresses such vulnerabilities through regular security updates and patches, while organizations should maintain up-to-date systems and consider implementing additional monitoring for unusual graphics API usage patterns. The vulnerability demonstrates the importance of robust memory safety practices in kernel-mode components and aligns with ATT&CK technique T1068 which covers local privilege escalation through kernel exploits and information disclosure mechanisms.