CVE-2026-113030 in Chrome
Summary
by MITRE • 10/21/2026
Improper access control in V8 in Google Chrome prior to 156.0.8078.47 allowed a remote attacker to potentially bypass web origin policy via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 10/21/2026
The vulnerability identified as an improper access control flaw within the V8 JavaScript engine of Google Chrome prior to version 156.0.8078.47 represents a significant deviation from expected browser isolation boundaries. This issue stems from a logical error in how the engine handles object references and property accesses across different execution contexts, specifically when dealing with cross-origin frames or workers. The V8 engine is responsible for parsing, compiling, and executing JavaScript code within Chrome's multi-process architecture. When an attacker crafts a malicious HTML page that leverages specific edge cases in prototype chains or getter/setter implementations, they can exploit the lack of strict validation on object ownership during property resolution. This allows scripts running in one origin to indirectly access properties or methods belonging to objects instantiated by another origin, effectively breaking the same-origin policy which is fundamental to web security.
From a technical perspective, this flaw aligns with CWE-269, Improper Privilege Management, and more specifically CWE-862, Missing Authorization Check within the context of client-side execution environments. The attack vector relies on social engineering or drive-by download tactics where a victim is directed to a malicious website containing specially crafted JavaScript code. By manipulating how V8 resolves property lookups during garbage collection cycles or cross-context evaluations, an attacker can read sensitive data such as cookies, local storage contents, or DOM elements from the target origin without explicit permission. This bypasses the browser's built-in security mechanisms that are designed to prevent scripts on one page from interacting with content from another unrelated site, a core tenet of web application security known as cross-origin resource sharing restrictions.
The operational impact of this vulnerability is severe for users browsing untrusted websites or visiting compromised legitimate sites that have been injected with malicious payloads. An attacker who successfully exploits this flaw can perform data exfiltration by reading sensitive information stored in the victim's browser session, such as authentication tokens, personal identifiable information, or financial details. Furthermore, the ability to bypass origin policies enables sophisticated cross-site scripting attacks and clickjacking variants that were previously mitigated by strict isolation boundaries. This compromises user privacy and can lead to account takeover if combined with other vulnerabilities like CSRF token theft. The Chromium security team has classified this issue as Medium severity because while it allows for significant data leakage, it typically requires a specific crafted environment rather than being exploitable through simple URL manipulation alone, though the ease of crafting such pages makes widespread exploitation feasible.
To mitigate the risks associated with this vulnerability, immediate action is required to update Google Chrome and all Chromium-based browsers to version 156.0.8078.47 or later. This patch includes corrections in the V8 engine's object model handling that enforce stricter checks on cross-origin property access. For organizations deploying enterprise versions of these browsers, it is advisable to verify that automatic update policies are enabled and functioning correctly across all endpoints. Additionally, security teams should monitor for indicators of compromise related to unusual JavaScript execution patterns or unexpected network requests originating from browser processes, which may indicate exploitation attempts before patches are applied. Implementing Content Security Policy headers with strict directives can also provide an additional layer of defense by limiting the sources from which scripts can be loaded and executed, thereby reducing the attack surface available to adversaries attempting to leverage this flaw.
This incident underscores the critical importance of maintaining up-to-date browser versions in both personal and enterprise environments. The complexity of modern web engines like V8 means that even minor logical errors in access control logic can have profound security implications. Security professionals should treat such vulnerabilities as high-priority issues due to their direct impact on user data confidentiality and integrity. Regular vulnerability scanning and patch management cycles are essential defenses against these types of client-side exploits. Furthermore, educating users about the risks of visiting untrusted websites remains a vital component of a holistic security strategy, as technical controls alone cannot prevent all forms of social engineering that lead to exploitation of browser vulnerabilities.