CVE-2026-106194 in Chrome
Summary
by MITRE • 10/06/2026
Missing authorization in WebAppInstalls in Google Chrome prior to 155.0.8059.39 allowed a remote attacker who had compromised the renderer process and leveraged social engineering to potentially execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 10/06/2026
The vulnerability identified in Google Chrome prior to version 155.0.8059.39 represents a critical failure in access control mechanisms within the WebAppInstalls component of the Chromium browser engine. This flaw is classified as a missing authorization issue, which fundamentally allows an attacker who has already achieved partial compromise of the renderer process to escalate privileges and escape the security sandbox. The severity of this vulnerability is rated as Medium by the Chromium team, reflecting its potential for significant impact despite requiring specific preconditions such as social engineering or prior renderer exploitation. This type of flaw undermines one of the core tenets of modern web browser architecture: strict isolation between untrusted content loaded from websites and sensitive system resources accessible to the user profile and operating system.
From a technical perspective, the WebAppInstalls functionality is responsible for managing Progressive Web Apps (PWAs) that users choose to install on their devices. These applications operate with elevated privileges compared to standard web pages because they are granted access to native device features such as file systems, notifications, and background sync capabilities. The vulnerability arises when the browser fails to properly verify whether a request originating from an installed PWA context is authorized by the user or adheres to expected security boundaries. An attacker leveraging this flaw can craft malicious HTML content that exploits these insufficient checks. By manipulating the installation process or interacting with existing web app instances, the attacker bypasses intended restrictions, effectively tricking the browser into executing code in a higher-privilege environment than permitted for standard web contexts.
The operational impact of this vulnerability is severe because it facilitates sandbox escape, which is one of the most dangerous outcomes in browser security research. Once an attacker escapes the renderer process sandbox, they gain the ability to execute arbitrary code with the same privileges as the user running the browser. This can lead to full system compromise, including data theft, installation of persistent malware, and lateral movement within a network if the compromised machine is part of a larger infrastructure. The requirement for social engineering indicates that this vulnerability cannot be exploited entirely autonomously through passive web browsing alone; it typically requires an attacker to deceive a user into visiting a crafted page or interacting with a maliciously designed PWA interface. This dependency on human interaction does not diminish the severity but rather highlights the importance of defense-in-depth strategies, as technical controls must assume that users may be tricked by sophisticated phishing campaigns.
In terms of industry standards and threat modeling, this vulnerability aligns closely with CWE-269, which describes Improper Privilege Management, specifically where an actor is able to obtain privileges or permissions it should not have access to. Furthermore, the exploitation path maps directly to MITRE ATT&CK techniques related to Defense Evasion and Command and Scripting Interpreter execution within a sandboxed environment. The attacker’s ability to leverage social engineering corresponds to initial access vectors often seen in targeted attacks where human factors are exploited alongside technical flaws. Understanding this mapping helps security teams prioritize patching efforts, as vulnerabilities enabling sandbox escapes are consistently prioritized due to their potential for widespread impact and ease of exploitation once the initial foothold is gained.
Mitigation strategies primarily involve immediate application of the vendor-provided patches included in Google Chrome version 155.0.8059.39 or later. Organizations should enforce automated update policies across all endpoints to ensure that browser versions remain current, thereby closing known gaps before they can be actively exploited by threat actors. Additionally, implementing strict Content Security Policies and restricting the installation of third-party Progressive Web Apps can reduce the attack surface available for such exploits. User education remains a critical component of defense; training personnel to recognize suspicious links or unusual prompts related to application installations can prevent the initial social engineering step required to trigger this vulnerability. Regular security audits focusing on browser configuration and extension management further strengthen the overall posture against privilege escalation attacks targeting web applications.