CVE-2026-79191 in Chrome
Summary
by MITRE • 08/26/2026
Incorrect authorization in SiteIsolation in Google Chrome prior to 152.0.7977.65 allowed a remote attacker who had compromised the renderer process and leveraged social engineering to bypass site isolation via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 08/26/2026
The vulnerability identified as an incorrect authorization flaw within Google Chrome's SiteIsolation mechanism prior to version 152.0.7977.65 represents a significant breach in the browser's process isolation architecture. SiteIsolation is a critical security feature designed to prevent cross-site scripting attacks and data theft by ensuring that each site runs in its own unique operating system process, thereby preventing malicious scripts from accessing sensitive information belonging to other sites. The flaw arises when the authorization checks governing this isolation are not strictly enforced under specific conditions, allowing for potential boundary violations between different origins or security contexts within the browser environment.
The technical nature of this vulnerability involves a logic error in how Chrome validates permissions during cross-origin navigation and resource loading operations. When an attacker compromises a renderer process through social engineering techniques such as phishing or malicious web content injection, they can exploit this authorization gap to bypass SiteIsolation protections. By crafting specific HTML pages that leverage these misconfigurations, the attacker can trick the browser into treating data from one origin as if it belongs to another, effectively breaking the sandbox boundaries intended to contain potential exploits within a single process.
From an operational perspective, the impact of this vulnerability is severe for users who interact with untrusted web content. Successful exploitation allows a remote attacker to access sensitive user data such as cookies, local storage contents, and session tokens from other sites that should remain isolated due to Same-Origin Policy restrictions. This capability undermines the fundamental trust model of modern web browsers, potentially leading to account takeover, identity theft, or further lateral movement within compromised systems where browser sessions are used for authentication.
This vulnerability aligns with Common Weakness Enumeration category CWE-269, which covers Improper Authorization, specifically in contexts where access control decisions fail to properly restrict actions based on user roles or security context. In terms of the MITRE ATT&CK framework, this flaw facilitates techniques associated with Initial Access and Credential Access, particularly those involving browser-based attacks like phishing for credentials or stealing session cookies through cross-site scripting variants that bypass isolation mechanisms.
Mitigation strategies primarily involve updating Google Chrome to version 152.0.7977.65 or later where these authorization checks have been corrected to strictly enforce process boundaries regardless of the rendering context. Organizations should ensure automated patch management processes are in place to apply security updates promptly upon release. Additionally, users can reduce risk by employing browser extensions that enhance site isolation policies and avoiding interaction with untrusted web content until patches are applied. Security teams should monitor for indicators of compromise related to renderer process anomalies or unexpected cross-origin data access patterns as part of their threat detection efforts.