Description

Insufficient policy enforcement in Navigation in Google Chrome prior to 151.0.7922.109 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page. (Chromium security severity: High)

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.3",
  "pubDate": "2026-08-06T22:16:57.437Z",
  "pubdate": "2026-08-06T22:16:57.437Z",
  "executiveSummary": "A high-severity vulnerability involving insufficient policy enforcement within the Navigation component of Google Chrome prior to version 151.0.7922.109 has been identified. This security flaw allows a remote attacker who has already successfully compromised the renderer process to potentially execute a sandbox escape by leveraging a specially crafted HTML page. The vulnerability presents significant risk implications, as breaking out of the Chromium security sandbox compromises the underlying process isolation model, potentially exposing the host operating system and user data to arbitrary code execution and further compromise. Successful exploitation requires the attacker to first achieve code execution within the renderer process, typically by luring a user to a malicious web page designed to trigger the flaw during navigation handling. The vulnerability affects all Google Chrome instances running software versions preceding 151.0.7922.109. Immediate remediation requires updating the browser to the patched version to restore proper policy enforcement and maintain boundary integrity between the rendering engine and the host environment.",
  "technicalDetails": "The vulnerability stems from insufficient policy enforcement mechanisms within the Navigation component of Google Chrome prior to version 151.0.7922.109. The Chromium security architecture relies on strict process isolation and privilege boundaries, separating the high-privilege browser process from the untrusted, sandboxed renderer processes responsible for parsing and rendering web content such as HTML, JavaScript, and CSS. The root cause of this flaw lies in the inadequate validation and enforcement of security policies during navigation transitions, allowing malicious logic or manipulated state parameters to cross privilege boundaries.\nThe exploitation vector requires an attacker to first compromise the untrusted renderer process, which can be achieved through a separate vulnerability or by utilizing malicious JavaScript logic executed within the context of a crafted HTML page loaded by the victim. Once control over the renderer process is established, the attacker crafts specific inputs and navigation requests designed to exploit the policy enforcement gaps in the Navigation subsystem. Through precise manipulation of navigation parameters and inter-process communication (IPC) channels between the renderer and the browser process, the attacker bypasses intended security checks.\nThe attack flow proceeds as follows: First, the user navigates to a malicious, attacker-controlled URL serving the crafted HTML page. Second, execution of the malicious content triggers anomalous behavior or exploits memory corruption within the renderer process, securing execution context. Third, the compromised renderer initiates a crafted navigation sequence that exploits the insufficient policy enforcement logic within the Navigation component. Fourth, by exploiting these policy blind spots, the attacker induces the browser process or privileged utility processes to perform unauthorized actions or expose internal interfaces. Finally, this grants the attacker the ability to escape the sandbox boundaries, transitioning from the restricted renderer context to higher-privilege execution levels on the host system. Post-exploitation impact includes arbitrary code execution outside the browser sandbox, potentially leading to full system compromise depending on the privileges of the executing user account."
}