CVE-2026-87541 in Chrome
Summary
by MITRE • 09/09/2026
Information leak in Navigation in Google Chrome prior to 153.0.8010.36 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified as an information leak within the navigation logic of Google Chrome prior to version 153.0.8010.36 represents a significant breach in browser security architecture, specifically targeting the site isolation mechanism. Site isolation is a critical defense-in-depth strategy employed by modern web browsers to prevent cross-site attacks such as Spectre-style side-channel exploits and data theft across different origins. By enforcing strict boundaries between browsing contexts belonging to distinct sites, Chrome ensures that sensitive information from one origin cannot be accessed or inferred by another. The flaw in the navigation process allowed a remote attacker who had already achieved code execution within a renderer process to circumvent these isolation guarantees. This bypass was facilitated through the manipulation of crafted HTML pages designed to exploit specific edge cases in how the browser handles state transitions and context switching during page loads, effectively weakening the sandbox boundaries that protect user data from malicious scripts running on untrusted websites.
From a technical perspective, this vulnerability falls under the category of improper access control within the navigation subsystem, aligning with CWE-200: Information Exposure. The core issue lies in the renderer process's ability to leak state or memory information across site boundaries during navigation events. When a user navigates between pages, especially those involving complex JavaScript execution or frame manipulations, the browser must ensure that no residual data from the previous context persists in a way that can be observed by the new context if they belong to different origins. The flaw allowed an attacker leveraging a compromised renderer process to observe these leaks, thereby gaining insights into the browsing session of other tabs or windows belonging to different sites. This capability undermines the fundamental assumption of site isolation, which posits that malicious code on one origin should have zero visibility into resources from another origin unless explicitly permitted by web standards like CORS.
The operational impact of this vulnerability is severe for users who rely on Chrome for handling sensitive information such as banking credentials, personal identification data, or corporate secrets. An attacker capable of exploiting this flaw could potentially perform cross-site tracking with unprecedented precision, bypassing privacy controls and anti-fingerprinting measures that depend on site isolation to function correctly. Furthermore, the ability to leak information across origins can serve as a stepping stone for more sophisticated attacks, including privilege escalation within the browser's sandbox or facilitating further exploitation of other vulnerabilities by providing accurate environmental data about the victim's browsing context. The Chromium security team classified this issue with a medium severity rating, reflecting its potential to compromise user privacy and integrity without necessarily leading directly to full system compromise on its own.
To mitigate the risks associated with this vulnerability, users are strongly advised to update Google Chrome immediately to version 153.0.8010.36 or later, where these navigation logic flaws have been addressed through rigorous code reviews and enhanced validation checks within the browser's core components. For organizations deploying Chrome at scale, it is imperative to enforce automatic updates via group policy settings to ensure all endpoints are protected against such exploits. Additionally, security teams should monitor for indicators of compromise that suggest attempts to exploit renderer process vulnerabilities, as these often precede more severe attacks. Maintaining up-to-date browser versions remains the most effective defense against known navigation-based information leaks and other site isolation bypasses documented in industry standards like MITRE ATT&CK technique T1059: Command and Scripting Interpreter when used for initial access or lateral movement within a compromised environment.