CVE-2026-106427 in Chrome
Summary
by MITRE • 10/07/2026
Confused deputy in Mobile in Google Chrome on on iOS prior to 155.0.8059.39 allowed a remote attacker to bypass system access restrictions into a privileged page 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 a confused deputy flaw in Google Chrome for iOS prior to version 155.0.8059.39 represents a significant breach of the principle of least privilege within the mobile browser environment. This specific class of vulnerabilities occurs when an application, acting on behalf of a user or another process, inadvertently performs actions with elevated privileges that were not intended for its current context. In this instance, the Chromium engine failed to properly validate whether the requesting entity had the necessary authorization to access certain privileged resources within the iOS operating system. The flaw allowed a remote attacker to exploit this misconfiguration by crafting a malicious HTML page designed to trigger unauthorized API calls or resource accesses that should have been blocked by the browser's security sandbox and the underlying mobile OS permissions model.
From a technical perspective, the core issue lies in the improper separation of duties between different execution contexts within the Chrome for iOS architecture. When a webpage attempts to interact with system-level features such as location services, camera access, or sensitive file systems, the browser is supposed to act as an intermediary that checks user consent and OS-level permissions before granting access. However, due to this confused deputy vulnerability, the browser erroneously forwarded these requests to privileged pages or internal components without sufficient verification of the caller's identity or intent. This allowed a remote attacker, who could only influence the content served via a crafted HTML page, to bypass standard system access restrictions and execute code or retrieve data in a context that typically requires higher trust levels than those granted to untrusted web content.
The operational impact of this vulnerability is primarily centered on privacy violations and potential unauthorized data exfiltration. By bypassing system access restrictions, an attacker could potentially gain read-only or write access to sensitive user information stored within the browser's privileged scope, such as cookies, local storage, or cached credentials that are normally shielded from web page scripts. While the Chromium security severity is classified as Low, indicating that exploitation may require specific conditions or limited impact on system integrity, the ability to bypass iOS sandboxing mechanisms poses a risk to user confidentiality. An attacker leveraging this flaw could construct sophisticated phishing campaigns where malicious sites silently harvest sensitive data without triggering standard permission prompts, thereby undermining the trust model of mobile web browsing and exposing users to identity theft or further targeted attacks based on harvested personal information.
Mitigation strategies for this vulnerability rely heavily on timely software updates and robust security hygiene practices. The primary remediation is to upgrade Google Chrome for iOS to version 155.0.8059.39 or later, where the confused deputy logic has been corrected to ensure that privileged operations are strictly validated against the caller's actual permissions. Users should enable automatic update notifications to ensure they receive patches promptly as they become available. Additionally, from a defensive posture perspective, users can mitigate risks by disabling JavaScript for untrusted sites if their workflow permits, although this significantly degrades web usability. Security teams and individual users alike must remain vigilant against social engineering tactics that encourage the opening of unfamiliar or suspicious URLs, as these are the primary vectors through which such crafted HTML pages are delivered to victims.
This incident aligns with Common Weakness Enumeration (CWE) category CWE-269, which describes Improper Privilege Management, specifically highlighting scenarios where a program executes more functions than it is authorized to perform due to flawed access control logic. Furthermore, the exploitation technique maps to MITRE ATT&CK techniques related to Initial Access and Defense Evasion, particularly those involving browser-based attacks that bypass security restrictions through crafted content. Understanding this vulnerability in the context of these industry standards helps emphasize the importance of rigorous input validation and strict enforcement of privilege boundaries within web browsers, especially on mobile platforms where the attack surface includes both application-level code and operating system interfaces. Continuous monitoring for similar patterns in future updates remains essential to maintaining a secure browsing environment against evolving browser-based threats.