CVE-2026-76019 in Chrome
Summary
by MITRE • 08/21/2026
Incorrect authorization in Workers in Google Chrome prior to 151.0.7922.173 allowed a remote attacker who had compromised the renderer process and leveraged social engineering to bypass web origin policy via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 08/21/2026
The vulnerability identified in Google Chrome prior to version 151.0.7922.173 represents a critical failure in the enforcement of access controls within the browser's worker execution environment. This flaw, classified as an incorrect authorization issue, specifically affects Web Workers and Service Workers which are designed to run scripts in background threads separate from the main page execution thread. The core technical deficiency lies in the insufficient validation of origin policies when these workers attempt to interact with resources or APIs that should be restricted by their originating context. In a properly secured browser architecture, each worker is bound strictly to its source origin, ensuring it cannot access data or perform actions on behalf of other origins without explicit permission. However, due to this implementation error, the boundary between different web origins becomes permeable under specific conditions involving renderer process compromise and social engineering tactics.
The operational impact of this vulnerability allows a remote attacker who has already achieved code execution within the browser's renderer process to escalate their privileges significantly. By leveraging social engineering techniques such as phishing or malicious website redirection, an attacker can craft a specially designed HTML page that exploits this authorization bypass. Once executed, the crafted script utilizes the flawed worker mechanism to circumvent web origin policies. This effectively allows the attacker to read sensitive data from other domains, manipulate cross-origin resources, or perform actions on behalf of users in contexts where they should not have access. The severity is rated as high because it undermines one of the fundamental security models of the modern web: same-origin policy, which is essential for preventing unauthorized data leakage and session hijacking attacks.
From a classification perspective, this vulnerability aligns with CWE-269, Improper Privilege Management, specifically regarding the failure to enforce required permissions before granting access to system resources or sensitive data. It also maps closely to ATT&CK technique T1059, Command and Scripting Interpreter, as it involves the execution of scripts within a browser environment to achieve unauthorized objectives. Furthermore, the bypass of web origin policies relates directly to CWE-284, Improper Access Control, highlighting the breakdown in verifying that an actor has the necessary rights for their requested action. The exploitation chain relies heavily on the initial compromise of the renderer process, which is often achieved through other vulnerabilities or malicious content delivery networks, making this a secondary but potent escalation vector.
Mitigation strategies primarily involve updating to Google Chrome version 151.0.7922.173 or later, where these authorization checks have been corrected and strengthened. For organizations unable to patch immediately due to compatibility concerns, implementing strict Content Security Policy headers can help mitigate the risk by restricting the sources from which scripts are allowed to execute. Additionally, disabling JavaScript for untrusted sites via browser settings provides a robust defense against such social engineering attacks that rely on script execution. Users should remain vigilant regarding suspicious links and websites, as the initial entry point often involves deceptive user interaction. Regular security audits of web applications hosted by organizations can also help identify if any internal services are vulnerable to cross-origin data leakage resulting from similar implementation flaws in their own codebases.