Description

Access of resource using incompatible type ('type confusion') in Microsoft Edge (Chromium-based) allows an unauthorized attacker to execute code over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-28T20:19:44.943Z",
  "pubdate": "2026-08-28T20:19:44.943Z",
  "executiveSummary": "This vulnerability involves a type confusion flaw within Microsoft Edge, based on the Chromium engine. A type confusion occurs when the application initializes or accesses a resource using an incompatible type, leading to undefined behavior in memory management.\nThe vulnerability allows a remote, unauthorized attacker to execute arbitrary code over a network by interacting with the affected browser process. Successful exploitation can result in full system compromise, data exfiltration, or the installation of malicious software.\nThe flaw affects Microsoft Edge (Chromium-based) installations. Given the nature of type confusion in browser engines, the exploitation process typically involves crafting a malicious web page that tricks the rendering engine into performing operations on incorrect object types.\nThe risk is critical due to the potential for remote code execution (RCE) without user interaction beyond navigating to a malicious site. Organizations should prioritize updating the browser to the latest version to incorporate patches provided by the vendor.",
  "technicalDetails": "The root cause of this vulnerability is a type confusion bug within the Microsoft Edge rendering engine (Chromium). Type confusion occurs when the engine's memory safety mechanisms fail to correctly validate the expected type of an object during runtime operations, particularly within the JIT (Just-In-Time) compiler or the DOM (Document Object Model) object handling logic.\nDuring execution, the engine may perform an operation on an object assuming it is of a specific class or structure. If an attacker can manipulate the state of the heap or the execution flow to supply an object of an incompatible type, the engine may process the object incorrectly, leading to a memory safety violation. This typically manifests as a read/write access violation in unintended memory locations.\nThe attack flow generally proceeds as follows: First, an attacker hosts a maliciously crafted webpage containing scripts designed to trigger the type confusion, often leveraging vulnerabilities in the way the browser manages memory for complex objects or arrays. Second, the attacker induces the browser to perform specific operations (such as property access or function calls) on these malformed objects.\nBy successfully triggering the confusion, the attacker gains the ability to overwrite critical data structures, such as object pointers or function vtables. This allows the attacker to redirect the browser's execution flow to arbitrary attacker-controlled memory segments, facilitating the execution of shellcode or Return-Oriented Programming (ROP) chains.\nThe exploitation does not require prior authentication, as it is triggered by standard network interaction (browsing to an attacker-controlled URI). The attack requires the victim's browser to execute the malicious code, often bypassing Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) through advanced heap grooming techniques.\nPost-exploitation, the attacker operates within the security context of the browser process. Depending on the sandbox implementation, the attacker may attempt to escape the browser sandbox to gain higher-level privileges on the underlying operating system, allowing for persistent access, credential harvesting, and lateral movement within the network."
}