Description

Heap-based buffer overflow in Microsoft Edge (Chromium-based) allows an unauthorized attacker to execute code over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.3",
  "pubDate": "2026-08-14T18:19:09.003Z",
  "pubdate": "2026-08-14T18:19:09.003Z",
  "executiveSummary": "This vulnerability is classified as a heap-based buffer overflow affecting Microsoft Edge (Chromium-based). The security flaw permits an unauthorized remote attacker to achieve arbitrary code execution over a network. The primary risk implication involves total compromise of the affected browser process, potentially leading to system compromise depending on the execution context and sandbox integrity. Exploitation requires the target user to interact with malicious content over the network, such as browsing to a compromised or malicious web page controlled by the threat actor. No advanced privileges or prior authentication are required on the target system to initiate the attack vector, making network-based exploitation highly dangerous if weaponized in the wild.",
  "technicalDetails": "The vulnerability stems from a memory management flaw specifically residing within the heap-based memory allocation mechanisms of Microsoft Edge (Chromium-based). A heap-based buffer overflow occurs when dynamic memory allocated on the heap is written to with a data size larger than the allocated buffer, resulting in memory corruption of adjacent heap structures. In the context of this Chromium-based architecture, improper bounds checking during the processing of complex web inputs or data structures allows malicious payloads to overwrite critical metadata or function pointers residing on the heap.\nThe attack flow begins when an unauthorized remote attacker delivers a crafted payload over a network, typically via a malicious website or compromised web application accessed by the victim using Microsoft Edge. Upon parsing the malicious input, the vulnerable component fails to properly validate the size of the incoming data against the pre-allocated heap buffer boundaries. Consequently, the overflow occurs, corrupting adjacent heap chunks.\nAn attacker can carefully manipulate the heap layout through heap grooming or massaging techniques prior to triggering the overflow. By overwriting specific function pointers or objects residing in heap memory, the attacker can hijack the normal control flow of the application when the corrupted pointers are subsequently dereferenced. This results in arbitrary code execution within the security context of the running browser process or sandbox container.\nNetwork exposure is fully present as the attack vector requires remote interaction over standard network protocols (e.g., HTTP/HTTPS). The vulnerability can be exploited without any prior authentication by the attacker, and the victim needs no special privileges to encounter the trigger condition beyond standard browsing activity. Post-exploitation impact includes the potential execution of arbitrary shellcode, local privilege escalation if sandbox escape vulnerabilities are chained, or unauthorized access to sensitive user data managed by the browser instance."
}