CVE-2026-95342 in Chrome
Summary
by MITRE • 09/29/2026
Missing authorization in V8 in Google Chrome prior to 154.0.8037.57 allowed a remote attacker to bypass web origin policy via a crafted HTML page. (Chromium security severity: Low)
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/29/2026
The vulnerability identified as missing authorization within the V8 JavaScript engine of Google Chrome represents a critical failure in access control mechanisms that governs how scripts interact with browser-originated resources. This flaw, present in versions prior to 154.0.8037.57, fundamentally undermines the web origin policy, which is a core security concept designed to isolate potentially malicious documents from sensitive data and other websites. The V8 engine serves as the JavaScript runtime for Chrome, handling the execution of code embedded within web pages. When authorization checks are omitted or improperly implemented during specific operations involving cross-origin requests or resource access, it creates an avenue for attackers to manipulate these boundaries. This is not merely a logic error but a structural weakness in how the browser validates whether a script from one origin has legitimate permission to interact with resources belonging to another origin.
From a technical perspective, this vulnerability allows a remote attacker to bypass web origin policies through the delivery of a crafted HTML page. The attack vector typically involves social engineering or drive-by download tactics where an unsuspecting user visits a malicious website containing specially constructed code. This code exploits the lack of proper authorization checks within V8 to perform actions that should be restricted by same-origin policy rules. For instance, it may enable unauthorized reading of data from other domains, such as cookies, local storage, or DOM elements belonging to a different origin. The severity is classified as low in Chromium security metrics because while the bypass exists, its practical exploitation often requires specific conditions or user interaction that limit widespread automated abuse. However, even low-severity vulnerabilities can be chained with others to achieve significant impacts like session hijacking or data exfiltration.
The operational impact of this vulnerability centers on the erosion of trust in the browser's security model. Web origin policies are essential for preventing cross-site scripting attacks and unauthorized data access across different websites. By bypassing these controls, an attacker can potentially access sensitive user information that is stored locally by other applications or services running within the same browser profile. This could lead to privacy violations where personal data, financial details, or authentication tokens are exposed without consent. Furthermore, it compromises the integrity of web applications that rely on strict origin enforcement for security, such as banking portals or email clients. Users relying on Chrome for secure browsing face increased risk when visiting compromised or malicious sites that leverage this flaw to escalate privileges within their browser environment.
Mitigation strategies primarily involve updating Google Chrome to version 154.0.8037.57 or later, where the authorization checks in V8 have been corrected. Administrators should ensure automatic updates are enabled for all endpoints using Chrome to maintain protection against known vulnerabilities. For organizations deploying Chrome via enterprise policies, enforcing update schedules is critical to minimize exposure windows. Additionally, users can employ browser extensions that enforce strict content security policies or block scripts from unknown origins as a defensive layer. Security awareness training remains vital, teaching users to recognize and avoid suspicious links or downloads that might trigger such exploits. Monitoring network traffic for anomalous cross-origin requests can also help detect potential exploitation attempts in real-time within enterprise environments.
This vulnerability aligns with CWE-284, which describes Improper Access Control, specifically highlighting failures in authorization checks that allow unauthorized access to resources. It is closely related to the ATT&CK technique T1059, Command and Scripting Interpreter, as it involves executing code (JavaScript) within a browser context to achieve malicious objectives. The bypass of web origin policies also maps to MITRE ATT&CK sub-technique T1078.004, Valid Accounts: Local Accounts, if the attack leverages existing user sessions or credentials stored in the browser profile. Understanding these mappings helps security teams categorize and prioritize remediation efforts based on established industry frameworks for vulnerability management and threat intelligence integration.