Description

Race condition in Extensions in Google Chrome prior to 152.0.7977.65 allowed a remote attacker to bypass system access restrictions via a crafted Chrome extension. (Chromium security severity: Low)

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.5",
  "pubDate": "2026-08-25T21:17:57.520Z",
  "pubdate": "2026-08-25T21:17:57.520Z",
  "executiveSummary": "A race condition vulnerability has been identified within the Google Chrome Extensions framework, affecting versions prior to 152.0.7977.65. This security flaw enables a remote attacker to bypass enforced system access restrictions, potentially leading to unauthorized operations within the browser environment.\nClassified with a Low severity rating by the Chromium security team, this vulnerability highlights a breakdown in the synchronization of state management during extension lifecycle events. The impact is primarily centered on the circumvention of security boundaries that normally constrain extension capabilities. Successful exploitation requires the delivery of a crafted Chrome extension designed to trigger the race condition, allowing an attacker to operate outside of defined security policies. The flaw poses a moderate risk to users who install extensions from untrusted sources, as it can lead to the subversion of Chrome's security model. Mitigation necessitates updating the Chromium engine to the specified patched version to ensure proper concurrency control within the extensions subsystem.",
  "technicalDetails": "The vulnerability originates from a race condition within the Chromium Extensions component. In the context of browser security, race conditions occur when the browser's execution logic fails to handle asynchronous operations or state transitions in a thread-safe manner, particularly when managing extension resources and permission grants. Specifically, this issue likely involves a lack of proper atomic synchronization between the loading, verification, and enforcement phases of an extension's configuration.\nThe exploitation flow initiates when a user is convinced to install or interact with a maliciously crafted Chrome extension. Because the browser's internal logic lacks sufficient mutex locking or atomic state management during the initialization phase, the extension can manipulate its own properties or the browser's security context during a window of time where validation checks are incomplete. By strategically timing the execution of extension setup tasks, an attacker creates an opportunity to invoke privileged APIs or access protected system resources that the extension should otherwise be prohibited from reaching.\nTechnically, the race condition occurs when the extensions subsystem checks system access restrictions against the extension's manifest or security context. If the internal state is updated by the extension process after the initial check but before the final enforcement of access control, the policy enforcement mechanism may operate on stale or inconsistent data. This temporal gap allows the extension to effectively 'race' the browser's security logic, resulting in the successful bypass of system access restrictions.\nThe vulnerable component resides within the Chromium extensions manager, specifically where the browser handles IPC (Inter-Process Communication) messages that request elevation or access to sensitive browser features. The vulnerability persists across versions of Chrome prior to 152.0.7977.65. Exploitation does not require authentication from the perspective of the browser engine itself, but it does rely on the successful installation of a malicious payload. The post-exploitation impact allows for the circumvention of permission-based security controls, potentially enabling the extension to execute actions normally blocked by the browser’s sandboxing and permission architecture."
}