CVE-2026-17839 in Chrome
Summary
by MITRE • 07/30/2026
Inappropriate implementation in Chrome for iOS in Google Chrome on iOS prior to 151.0.7922.72 allowed a remote attacker to perform UI spoofing via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 07/30/2026
The vulnerability identified in Google Chrome for iOS affects versions prior to 151.0.7922.72 and represents a significant UI spoofing risk that could be exploited by remote attackers through maliciously crafted HTML pages. This issue falls under the category of improper implementation where the browser fails to adequately validate or sanitize user-provided content, creating an avenue for attackers to manipulate the user interface in deceptive ways. The vulnerability manifests specifically within the iOS implementation of Chrome, highlighting platform-specific security considerations that differ from the desktop version.
The technical flaw stems from insufficient input validation and sanitization mechanisms within the browser's rendering engine when processing HTML content on iOS devices. Attackers can craft HTML pages that exploit the browser's handling of certain elements or attributes to create misleading user interface components that appear legitimate but actually serve malicious purposes. This allows for techniques such as fake authentication prompts, misleading navigation elements, or deceptive security warnings that could trick users into divulging sensitive information or performing unintended actions.
The operational impact of this vulnerability extends beyond simple deception as it creates a foundation for more sophisticated attacks including phishing attempts, credential theft, and social engineering campaigns. Users operating affected versions of Chrome for iOS face elevated risk when browsing untrusted websites, as the UI spoofing capability can be leveraged to make users believe they are interacting with legitimate services while actually engaging with attacker-controlled content. This vulnerability directly impacts user trust in the browser's security model and could lead to successful compromise of user credentials or sensitive data.
Security professionals should note this issue aligns with CWE-602 Client-Side Enforcement of Server-Side Security, where server-side protections are bypassed through client-side manipulation. The vulnerability also maps to ATT&CK technique T1531 Credential Access - Steal or Forge Authentication Certificates, as UI spoofing can be used to harvest user credentials through deceptive interfaces. Organizations should prioritize immediate deployment of Chrome version 151.0.7922.72 or later across all iOS devices to mitigate this risk. Additional mitigations include user education about recognizing suspicious interface elements and implementing network-level monitoring for malicious HTML content, though the primary defense remains updating to the patched browser version.
The vulnerability demonstrates the ongoing challenge of maintaining security in mobile browser environments where platform-specific rendering behaviors can introduce unexpected attack vectors. This issue underscores the importance of comprehensive testing across different platforms and the need for robust input validation mechanisms that consider all potential interaction points within the user interface. Regular security updates and patch management processes become critical in preventing exploitation of such implementation flaws that may not be immediately apparent during initial development or testing phases.
This particular vulnerability highlights how seemingly minor implementation gaps can create substantial security risks in browser environments where user trust and interface integrity are paramount. The medium severity classification reflects the balance between the exploitability of the vulnerability and the potential impact on user security, though the actual risk to individual users may vary based on their browsing habits and the specific malicious content deployed by attackers. Security teams should monitor for reports of exploitation attempts and maintain awareness of related threats targeting mobile browser environments.