CVE-2026-106306 in Chrome
Summary
by MITRE • 10/06/2026
Incorrect authorization in DevTools in Google Chrome prior to 155.0.8059.39 allowed a local attacker to bypass system access restrictions via a crafted HTML page. (Chromium security severity: Low)
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified as an incorrect authorization flaw within the Developer Tools component of Google Chrome, specifically affecting versions prior to 155.0.8059.39, represents a significant lapse in access control mechanisms designed to isolate privileged debugging interfaces from standard web content. This security issue arises because the browser failed to properly enforce separation boundaries between untrusted HTML pages and sensitive internal APIs exposed through DevTools. In typical usage scenarios, Developer Tools are intended for use by developers who have explicitly opened them on specific tabs or windows, granting those contexts elevated privileges such as access to local file systems, network interception capabilities, and direct manipulation of DOM structures. However, the flaw allowed a malicious actor leveraging a crafted HTML page hosted locally or served from a controlled environment to exploit this misconfiguration. By constructing a webpage that interacts with DevTools endpoints in an unauthorized manner, the attacker could bypass system-level access restrictions that are normally enforced by the browser's security model. This type of vulnerability is categorized under CWE-269, which denotes Improper Privilege Management, as it involves granting capabilities to entities without verifying their authorization level appropriately.
From a technical perspective, this flaw likely stems from insufficient validation checks when processing requests or events originating from web pages that attempt to interface with the Chrome DevTools Protocol. The Chromium security team classified this issue with low severity because the attack vector requires local access or user interaction, such as opening a specific page in an environment where DevTools are already active or can be triggered through social engineering tactics involving trusted-looking interfaces. Nevertheless, even low-severity vulnerabilities can have compounding effects when chained with other flaws. For instance, if combined with cross-site scripting or data exfiltration techniques, the ability to bypass access restrictions could lead to unauthorized reading of sensitive browser storage, cookies, or local files that are typically protected from web page access. The operational impact is primarily centered on confidentiality and integrity risks for users who rely on Chrome’s sandboxing mechanisms to protect their digital identity and stored credentials against malicious scripts running in tabs they do not fully trust.
In terms of threat modeling, this vulnerability aligns with ATT&CK technique T1059, Command and Scripting Interpreter, specifically when used in conjunction with local execution contexts that leverage browser APIs for unauthorized data access. It also relates to T1213, Data from Information Repositories, as the bypassed restrictions could potentially allow extraction of stored credentials or session tokens if those resources are accessible via DevTools interfaces without proper origin checks. The exploitation scenario typically involves an attacker creating a malicious HTML file that utilizes JavaScript to interact with Chrome’s internal debugging ports or APIs in ways not intended for public web pages. Since the attack requires local presence, it is less likely to be exploited remotely at scale but remains dangerous in environments where users frequently open files from untrusted sources while having developer tools enabled, either manually or through extensions that automate development workflows.
Mitigation strategies focus primarily on software updates and configuration hardening. Users must upgrade Google Chrome to version 155.0.8059.39 or later, which contains the necessary patches to enforce stricter authorization checks within the DevTools subsystem. This update ensures that only authorized contexts can invoke privileged functions through the developer interface, effectively closing the gap exploited by crafted HTML pages. Additionally, administrators should consider disabling Developer Tools for standard user profiles in enterprise environments where development activities are not required, thereby reducing the attack surface entirely. Security awareness training is also recommended to educate users about the risks of opening local files or visiting untrusted websites while having debugging tools active, as this practice increases exposure to such authorization bypasses. Regular patch management cycles and monitoring for browser version compliance remain critical components of maintaining a robust defense posture against these types of logic-based vulnerabilities in web browsers.