CVE-2026-121029 in Chrome
Summary
by MITRE • 11/03/2026
Incorrect authorization in ORB in Google Chrome prior to 157.0.8103.38 allowed a remote attacker to bypass site isolation via a crafted HTML page. (Chromium security severity: Low)
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Analysis
by VulDB Data Team • 11/03/2026
The vulnerability identified as an incorrect authorization issue within the Object Request Broker component of Google Chrome, specifically affecting versions prior to 157.0.8103.38, represents a significant breach in the browser's internal access control mechanisms. The Object Request Broker serves as a critical infrastructure element that facilitates communication between different processes and components within the Chromium architecture. When authorization checks are improperly implemented or bypassed within this layer, it undermines the fundamental security model designed to isolate web content from sensitive system resources and other browsing contexts. This flaw allows for unauthorized access patterns that deviate from the intended privilege boundaries established by the browser's developers.
The operational impact of this vulnerability centers on the ability of a remote attacker to circumvent site isolation protections through the delivery of a specially crafted HTML page. Site isolation is a core security feature in modern browsers like Chrome, designed to prevent cross-site attacks such as Spectre-style side-channel exploits and data leakage between different origins. By exploiting the authorization flaw in the ORB, an attacker can trick the browser into treating content from one origin as if it belongs to another or granting elevated privileges that should not be available to untrusted web pages. This effectively breaks down the walls intended to contain malicious scripts within their respective sandboxed environments, potentially allowing for data exfiltration or further exploitation of other vulnerabilities within the same browsing session.
From a technical classification perspective, this issue aligns with CWE-269, which denotes Improper Privilege Management, as it involves granting permissions that exceed what is necessary for normal operation. Furthermore, the technique used to bypass site isolation maps directly to ATT&CK tactic T1057, specifically sub-technique T1057.003 related to Browser Proxying or manipulation of browser internals to evade detection and restrictions. The low severity rating assigned by Chromium security teams likely reflects the complexity required for exploitation or the limited scope of immediate impact without additional chained vulnerabilities, but it remains a critical concern due to its direct attack on site isolation integrity.
Mitigation strategies primarily involve updating Google Chrome to version 157.0.8103.38 or later, where these authorization checks have been corrected and hardened against such bypass attempts. For organizations managing large fleets of devices, ensuring automated patch deployment is essential to close this window of exposure. Additionally, users should be educated on the risks of visiting untrusted websites that may host crafted HTML pages designed to trigger such vulnerabilities. While browser sandboxing provides a robust defense layer, it relies heavily on the integrity of internal components like the ORB; therefore, maintaining up-to-date software versions is the most effective countermeasure against this class of privilege escalation and isolation bypass attacks.