Description

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

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.5",
  "pubDate": "2026-08-11T17:18:54.330Z",
  "pubdate": "2026-08-11T17:18:54.330Z",
  "executiveSummary": "This vulnerability is an out-of-bounds read security flaw affecting the Windows Graphics Device Interface (GDI). The primary impact of this vulnerability is local information disclosure, allowing an unauthorized or locally authorized entity to access sensitive memory contents that should otherwise remain sequestered.\nThe affected system component is the Windows GDI subsystem, which handles graphical device interaction and rendering operations within the operating system architecture. Risk implications involve the potential exposure of critical kernel or application memory structures, which could subsequently be leveraged in multi-stage exploit chains to bypass defensive mitigations such as Address Space Layout Randomization (ASLR).\nTo achieve exploitation, an attacker must possess local execution capabilities on the target host system, functioning as an authorized user. The attack vector relies on local access, meaning remote network exploitation is not directly feasible via this specific vulnerability vector. The inherent complexity involves interacting with the vulnerable GDI subsystem to trigger memory read operations that exceed allocated buffer boundaries, thereby returning unauthorized data to the attacker-controlled process space.",
  "technicalDetails": "The root cause of the vulnerability stems from improper bounds checking within the Windows GDI component when processing specific graphical data structures or rendering requests. Specifically, when the affected subsystem parses malformed or maliciously crafted inputs, it fails to adequately validate the size and boundaries of the targeted memory buffer against the actual data being read.\nThe vulnerable component resides within the Windows GDI kernel-mode or user-mode graphics rendering libraries responsible for handling graphical object creation and manipulation. Because these routines often process complex data structures, a failure to enforce strict length constraints results in an out-of-bounds read condition.\nExploitation occurs through a step-by-step attack flow where a locally authenticated attacker executes a custom application or script designed to interact with the GDI application programming interfaces (APIs). The attacker passes carefully constructed parameters or graphical objects to the subsystem. When the vulnerable function processes these inputs, it reads memory addresses outside the designated buffer boundaries.\nThe payload behavior centers on capturing the out-of-bounds memory contents returned by the vulnerable GDI functions. This retrieved memory may contain sensitive pointer addresses, cryptographic keys, or stack data from other processes or the operating system kernel. Although this vulnerability is strictly an information disclosure flaw and does not inherently permit remote code execution or direct modification of system data, the leaked memory values provide critical primitives for defeating modern exploit mitigations.\nRegarding environmental and access constraints, the vulnerability requires local access to the target system. The execution context requires the attacker to be an authorized user capable of running code locally. The network exposure is negligible as the attack surface is exposed solely through local system calls and graphical subsystem interfaces rather than network-facing services."
}