Description

Out-of-bounds write in Windows Imaging Component allows an unauthorized attacker to execute code over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-09-08T18:20:04.910Z",
  "pubdate": "2026-09-08T18:20:04.910Z",
  "executiveSummary": "This vulnerability is an out-of-bounds (OOB) write flaw residing within the Windows Imaging Component (WIC), a critical system framework responsible for handling image processing and codec-related tasks.\nThe vulnerability allows an unauthenticated, remote attacker to trigger memory corruption by supplying a specially crafted image file, which, when parsed, results in an OOB write operation.\nSuccessful exploitation enables remote code execution (RCE) with the privileges of the application processing the malicious image. The impact ranges from unauthorized data access and integrity compromise to full system takeover.\nThe risk is significant due to the network-based attack vector, which does not necessitate prior authentication. The vulnerability poses a severe threat to any system that utilizes WIC to render or process image data, including web browsers, document viewers, and system-level shells.\nDefensive posture requires immediate application of security updates provided by the vendor, as this vulnerability represents a high-severity threat to Windows ecosystem integrity.",
  "technicalDetails": "The root cause of this vulnerability is an improper bounds check within the Windows Imaging Component's image decoding logic. When the component processes an image, it must allocate memory buffers based on header metadata fields. If these metadata fields—such as width, height, or pixel data dimensions—are maliciously crafted, the parser may fail to validate that the calculated buffer size aligns with the actual memory allocation.\nDuring the decoding sequence, the component attempts to write pixel data into the destination buffer. Because the bounds checking logic is flawed, the component executes a write operation at a memory offset that resides outside the intended boundaries of the allocated heap chunk. This behavior constitutes an out-of-bounds write primitive.\nThe attack flow begins when an attacker delivers a malformed image file to the target system via a network protocol or embedded content (e.g., within an email attachment, a malicious webpage, or a file transfer). When the victim's system or a specific application invokes the Windows Imaging Component to render the image, the malicious metadata is processed.\nUpon triggering the OOB write, the attacker can overwrite adjacent memory structures, such as object pointers or function pointers, within the heap. By carefully structuring the heap layout—often referred to as heap grooming—the attacker can redirect program execution flow to an attacker-controlled memory location containing malicious shellcode.\nThe vulnerability does not require local authentication or elevated privileges to initiate; the exploit is executed in the context of the user running the process that calls the WIC APIs. If the calling process runs with high integrity levels or system privileges, the payload will execute with those elevated permissions, facilitating a full system compromise. Post-exploitation behavior typically involves the injection of malicious modules into legitimate system processes to maintain persistence, harvest sensitive credentials, or exfiltrate data across the network."
}