Description

Use after free in Microsoft Edge (Chromium-based) allows an authorized attacker to execute code over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.5",
  "pubDate": "2026-09-11T16:17:46.080Z",
  "pubdate": "2026-09-11T16:17:46.080Z",
  "executiveSummary": "A critical use-after-free (UAF) memory corruption vulnerability exists within Microsoft Edge (Chromium-based), allowing a remote, authorized attacker to achieve arbitrary code execution. The vulnerability stems from improper memory management, where the application attempts to reference a memory location after the corresponding object has been deallocated. This flaw poses a significant security risk, as successful exploitation enables an attacker to compromise the integrity and confidentiality of the host system. The impact of this vulnerability allows for remote execution of malicious code, potentially leading to full system compromise. Exploitation requires the attacker to be authorized within the context of the network, though the exact interaction requirements may vary based on the specific triggering mechanism. Organizations are urged to prioritize updates and apply available security patches to mitigate the potential for remote exploitation.",
  "technicalDetails": "The vulnerability is characterized as a use-after-free (UAF) flaw residing within the memory management logic of the Chromium-based architecture utilized by Microsoft Edge. A use-after-free occurs when an application continues to utilize a pointer to a memory address after the heap memory at that address has been deallocated via a free() operation. In the context of complex web browsers, this typically occurs during the lifecycle management of Document Object Model (DOM) elements, script objects, or internal rendering structures.\nThe root cause involves a race condition or a logic error where the object's reference count is not correctly managed, leading to a dangling pointer. When the garbage collection process or the manual memory management routine releases the object, the dangling pointer remains in memory. If an attacker can trigger the re-allocation of this specific memory address with controlled data before the application attempts to access the dangling pointer, the browser will treat the attacker-supplied data as the original object. This allows for the manipulation of internal object states, such as virtual function tables (vtable) or property pointers.\nThe attack flow begins with the attacker inducing the browser to enter a specific state where the vulnerable object is deallocated. Following this, the attacker performs heap spraying or memory grooming to occupy the freed memory block with malicious payloads. When the browser subsequently accesses the dangling pointer, it diverts execution control to the attacker's supplied code. Given that the browser processes web content with elevated privileges relative to the user-space, a successful exploit facilitates remote code execution in the context of the browser process.\nBecause the underlying engine is Chromium-based, the vulnerability often affects the rendering pipeline or JavaScript engine (V8). The exploit does not necessarily require complex user interaction if a network-accessible vector is identified. Upon successful redirection of the control flow, the attacker can execute arbitrary instructions, potentially escaping the browser's sandbox environment, accessing sensitive local files, or installing persistent backdoors on the host machine. The lack of proper memory sanitization at the point of release and the re-use of memory segments provide the necessary primitives for a reliable exploit chain."
}