CVE-2026-17755 in Chrome
Summary
by MITRE • 07/30/2026
Incorrect security UI in Extensions in Google Chrome prior to 151.0.7922.72 allowed an attacker who convinced a user to install a malicious extension to perform UI spoofing via a crafted Chrome Extension. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 07/30/2026
This vulnerability represents a significant UI spoofing weakness in Google Chrome's extension management system that existed prior to version 151.0.7922.72. The flaw allowed malicious actors to exploit the browser's extension interface by crafting specially designed extensions that could deceive users into believing they were interacting with legitimate browser components. This security gap stemmed from inadequate validation of extension UI elements and insufficient sandboxing mechanisms that should have prevented malicious extensions from mimicking trusted chrome interfaces.
The technical implementation of this vulnerability was rooted in Chrome's extension permission system and user interface rendering processes. When users installed extensions, the browser failed to properly verify the authenticity of UI components presented by third-party extensions, particularly those related to security warnings, permission requests, or administrative interfaces. Attackers could leverage this weakness by creating extensions that displayed misleading interface elements designed to appear as legitimate Chrome prompts or security notifications, potentially tricking users into granting elevated permissions or entering sensitive information.
The operational impact of this vulnerability was substantial as it enabled attackers to conduct sophisticated social engineering campaigns against Chrome users. Users who were convinced to install malicious extensions could be tricked into believing they were seeing genuine browser security alerts, permission dialogs, or update notifications. This created opportunities for credential theft, unauthorized access to user data, and privilege escalation attacks where victims might unknowingly grant permissions that would allow the malicious extension to access their browsing sessions, cookies, or personal information.
This vulnerability aligns with several cybersecurity frameworks including CWE-602, which addresses client-side attack vectors where input validation occurs on the client side rather than the server side. The issue also maps to ATT&CK technique T1556.004 related to credential access through UI spoofing and social engineering. Organizations using Chrome browsers were particularly vulnerable as this flaw exploited user trust in browser interfaces, making it difficult for end users to distinguish between legitimate and malicious UI elements without technical expertise.
Mitigation strategies should have included immediate browser updates to patch the UI validation mechanisms, implementation of enhanced extension verification processes, and improved user interface sandboxing. Security teams needed to conduct thorough vulnerability assessments of existing Chrome installations and educate users about recognizing suspicious extension behavior. The fix implemented by Google likely involved strengthening the extension permission model, enhancing UI element validation, and introducing additional checks during the extension installation process to prevent malicious extensions from presenting deceptive interfaces that could mislead users into granting unauthorized access or performing unintended actions through carefully crafted phishing attempts within the browser environment itself.