CVE-2026-106326 in Chrome
Summary
by MITRE • 10/06/2026
Confused deputy in UI in Google Chrome on on Android prior to 155.0.8059.39 allowed a local attacker to bypass system access restrictions into a privileged page via a co-installed app. (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 Google Chrome user interface on Android represents a significant class of privilege escalation risks inherent in complex software architectures that rely on inter-process communication and permission delegation. This specific issue, resolved in version 155.0.8059.39, stems from an improper check of authorization when one process attempts to access resources controlled by another more privileged process. In this context, the user interface component of Chrome failed to adequately verify that the entity requesting a particular action or resource was indeed authorized to do so, rather than merely appearing to be such due to shared system identifiers or trust relationships established during installation. This architectural weakness allows an attacker who has gained local access through a co-installed application on the device to exploit this misconfiguration and bypass critical system access restrictions.
From a technical perspective, the core of the vulnerability lies in the failure to enforce strict identity verification before granting elevated privileges within the browser's privileged pages. When a malicious or compromised app is installed alongside Chrome, it can leverage shared permissions or intent filters that are not sufficiently scoped. By crafting specific requests that mimic legitimate system calls or UI interactions, the attacker tricks the Chrome process into treating untrusted input as trusted authority. This effectively allows the local attacker to execute actions within the browser context that should be restricted to higher-privilege entities, such as accessing sensitive user data, modifying security settings, or injecting malicious content into secure contexts. The severity is classified as medium by Chromium standards because while it requires a co-installed app and does not typically allow for arbitrary code execution directly from the web, it significantly undermines the isolation guarantees that protect user privacy and system integrity on mobile devices.
The operational impact of this vulnerability extends beyond simple data leakage to include potential compromise of session tokens and sensitive browsing history if the attacker can manipulate the UI state or intercept privileged operations. An adversary with local access could use this flaw to escalate their privileges within the Android sandbox, potentially leading to further exploitation vectors that target other applications or system services. This aligns closely with CWE-269, which describes Improper Privilege Management, where a program does not properly assign and manage elevated permissions for actions requiring them. Furthermore, in the context of the MITRE ATT&CK framework, this behavior corresponds to techniques involving privilege escalation via local exploits, specifically those that abuse misconfigured access controls or confused deputy scenarios within mobile operating systems. The ability to bypass system restrictions highlights a critical gap in how Android applications interact with browser processes when they share certain security contexts without rigorous validation of the caller's identity and intent.
Mitigation strategies for this vulnerability primarily involve applying the latest software updates provided by Google, which include patches that enforce stricter checks on privilege delegation within the Chrome UI layer. Developers must ensure that all inter-process communications are validated against explicit allowlists rather than relying on implicit trust relationships derived from co-installation or shared user IDs. Security best practices dictate implementing principle of least privilege across all components, ensuring that even if a confused deputy scenario is attempted, the requested action fails due to insufficient permissions. Additionally, users should maintain vigilance regarding app installations and review permission grants carefully, as this vulnerability exploits the trust placed in co-installed applications. Regularly updating Android system images and browser versions remains the most effective defense against such logic-based flaws that exploit architectural assumptions rather than memory corruption bugs.