CVE-2026-106286 in Chrome
Summary
by MITRE • 10/06/2026
Confused deputy in Omnibox in Google Chrome prior to 155.0.8059.39 allowed a remote attacker to bypass web origin policy via crafted network traffic. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified as a confused deputy flaw within the Omnibox component of Google Chrome, specifically in versions prior to 155.0.8059.39, represents a significant breach of web origin policies through sophisticated network traffic manipulation. This security severity is classified as Medium by Chromium developers, yet its implications for user privacy and data integrity are substantial. The core issue stems from the browser's internal decision-making process regarding how it handles input received via the address bar when interacting with external services or APIs. In this context, a confused deputy attack occurs when an application that has been granted certain privileges is tricked into performing actions on behalf of another user without proper authorization checks. Here, the Omnibox acts as the privileged entity that processes network requests initiated by the user's input, but fails to correctly validate whether those requests should be subject to strict origin-based restrictions intended to isolate web content from potentially malicious sources.
The technical flaw lies in how Chrome’s networking stack interprets and routes traffic generated through the omnibox interface when it involves cross-origin interactions. Typically, browsers enforce same-origin policies to prevent scripts loaded from one origin from accessing resources or performing actions on behalf of a different origin without explicit permission via mechanisms like CORS. However, due to this vulnerability, crafted network traffic could exploit ambiguities in how the browser distinguishes between legitimate user-initiated navigation and automated or script-driven requests that masquerade as such. An attacker can craft specific HTTP headers or URL structures that cause the browser to treat a cross-origin request as if it were same-origin or otherwise exempt from standard security checks. This allows the remote attacker to bypass origin policy restrictions, effectively gaining unauthorized access to sensitive data or functionality associated with different web origins.
From an operational perspective, this vulnerability enables remote attackers to conduct sophisticated phishing attacks, session hijacking attempts, and data exfiltration scenarios that would normally be blocked by browser security models. By circumventing the same-origin policy, an attacker can read responses from APIs hosted on other domains, potentially accessing user-specific information such as account details, personal identifiers, or financial records if those resources are not adequately protected against cross-site requests. The impact is particularly severe because it undermines one of the fundamental pillars of web security: isolation between different websites and applications running in the same browser context. Users browsing normally could inadvertently trigger these crafted network conditions through malicious links or embedded content that exploits this flaw, leading to unauthorized data access without any explicit user interaction beyond visiting a compromised page.
This vulnerability aligns with CWE-275, which describes incorrect handling of directionality trust relationships, and is closely related to CWE-918, where the server uses client-side control in ways not anticipated by its developers. In terms of MITRE ATT&CK framework mapping, this behavior corresponds to techniques involving browser-based attacks such as T1053 (Scheduled Task/Job) or more specifically T1204 (User Execution) combined with T1078 (Valid Accounts) if the attacker leverages stolen credentials obtained through the bypass. The exploitation vector is remote and requires no special privileges on the victim’s system, making it a high-risk issue for widespread deployment in malicious campaigns targeting Chrome users globally.
Mitigation strategies primarily involve upgrading to Google Chrome version 155.0.8059.39 or later, where this logic error has been corrected by enforcing stricter validation of origin headers and request contexts within the Omnibox processing pipeline. Organizations should ensure that all endpoints are updated promptly to eliminate exposure to this class of attacks. Additionally, implementing Content Security Policy (CSP) directives can provide an additional layer of defense by restricting which sources are allowed to execute scripts or load resources, thereby reducing the attack surface even if similar vulnerabilities exist in other components. Developers integrating third-party services should also audit their API endpoints for proper CORS configuration and ensure that sensitive operations require explicit user consent rather than relying solely on browser-enforced origin checks. Regular security audits focusing on cross-origin resource sharing behaviors will help identify potential misconfigurations before they can be exploited by adversaries leveraging confused deputy patterns in modern web browsers.