CVE-2026-106270 in Chrome
Summary
by MITRE • 10/06/2026
Incorrect authorization in WebAppInstalls in Google Chrome prior to 155.0.8059.39 allowed a remote attacker to spoof UI elements 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 WebAppInstalls component of Google Chrome prior to version 155.0.8059.39 represents a significant deviation from expected access control mechanisms in web application installation workflows. This issue stems from a failure by the browser engine to properly validate whether the initiating context possesses the requisite privileges for specific user interface operations associated with progressive web app installations or similar features. In modern browsers, the process of installing a web application involves several steps where the browser must interact with the operating system and render various UI elements such as confirmation dialogs, progress indicators, or installation banners. The flaw allows these interactions to be manipulated by external entities that should not have authority over them, specifically bypassing the intended security boundaries designed to prevent malicious actors from interfering with legitimate user experiences.
From a technical perspective, this vulnerability is classified under CWE-269, which denotes Improper Control of Interaction Frequency or Context in certain implementations, but more accurately aligns with CWE-862, Missing Authorization, as it involves the lack of proper checks to ensure that only authorized components can trigger specific UI behaviors. The root cause lies in the logic governing how Chrome handles requests from web pages during the installation phase. When a crafted HTML page is served by an attacker-controlled server, it can exploit this gap in authorization checks to inject or spoof user interface elements. These fabricated elements are designed to mimic legitimate browser prompts or system notifications, thereby deceiving the end-user into believing that a trusted entity initiated the action. This type of attack leverages the trust users place in their web browser's interface, turning a standard security feature into a vector for social engineering and deception.
The operational impact of this vulnerability is primarily centered around user confusion and potential credential or data theft through sophisticated phishing campaigns. By spoofing UI elements, an attacker can create fake installation prompts that appear to originate from Chrome itself or the operating system. A victim interacting with such a page might be tricked into clicking on malicious buttons disguised as legitimate install options, potentially leading to unintended consequences such as granting excessive permissions to a web application, downloading malware under the guise of an app installer, or entering sensitive information into a fake form embedded within the spoofed interface. Although the Chromium security severity is rated as Low, indicating that exploitation requires specific user interaction and does not allow for direct code execution or sandbox escape on its own, the risk remains significant due to the high level of trust users have in browser UI elements. This trust makes such attacks highly effective for social engineering purposes, where visual deception plays a critical role in bypassing human vigilance.
In terms of industry frameworks, this vulnerability maps closely to MITRE ATT&CK technique T1078, Valid Accounts or System Configuration Manipulation if it leads to unauthorized access, but more directly relates to T1566.002, Spearphishing Link, and potentially aspects of UI Redressing attacks where the attacker overlays malicious content over legitimate interfaces. The ability to spoof UI elements is a classic indicator of an attempt to manipulate user perception rather than exploit technical weaknesses in memory management or cryptographic protocols. Consequently, while it does not compromise the browser's core security model directly, it undermines the integrity of the human-computer interaction layer, which is increasingly targeted by advanced persistent threats and cybercriminal groups seeking high-yield returns through deception.
Mitigation for this vulnerability requires immediate action to ensure that all instances of Google Chrome are updated to version 155.0.8059.39 or later, where the authorization checks within WebAppInstalls have been corrected. Administrators should enforce automatic updates wherever possible to minimize the window of exposure. For users who cannot update immediately, employing browser extensions that block suspicious scripts or restrict installation permissions can provide a layer of defense against such UI spoofing attempts. Furthermore, user education remains critical; individuals should be trained to verify the source of any installation prompts and look for subtle discrepancies in design, typography, or behavior that might indicate a spoofed interface rather than a genuine browser notification. Regular security audits focusing on web application integration points can also help identify similar authorization flaws before they are exploited in the wild.