CVE-2026-16397 in Firefox
Summary
by MITRE • 07/21/2026
Clickjacking issue in the WebExtensions component in Firefox for Android. This vulnerability was fixed in Firefox 153.
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Analysis
by VulDB Data Team • 07/21/2026
The clickjacking vulnerability in Firefox for Android's WebExtensions component represents a significant security flaw that allows attackers to deceive users into unintentionally interacting with malicious content while believing they are engaging with legitimate web pages. This type of attack exploits the user interface layer by overlaying invisible or transparent elements over legitimate interface components, causing users to inadvertently perform actions they did not intend to execute.
The technical implementation of this vulnerability stems from insufficient protection mechanisms within Firefox's WebExtensions framework that govern how browser extensions interact with web content and user interfaces. When a malicious website loads a WebExtension that has been crafted to exploit this weakness, it can manipulate the visual presentation layer to create deceptive user experiences where legitimate buttons, links, or interactive elements appear to function normally while actually triggering malicious actions in the background. This flaw particularly affects Android users who rely on Firefox's mobile browser implementation.
The operational impact of this vulnerability extends beyond simple user deception to potentially enable more serious security breaches including unauthorized transactions, data exfiltration, and credential theft. Attackers could leverage this weakness to trick users into granting permissions to malicious extensions, clicking through phishing interfaces, or inadvertently executing harmful commands within the browser environment. The vulnerability is particularly dangerous in mobile contexts where users may be less vigilant about interface interactions and where touch-based navigation can be more easily manipulated.
Mitigation strategies for this clickjacking vulnerability involve implementing robust security measures including proper frame-busting techniques, ensuring adequate sandboxing of WebExtensions components, and maintaining strict origin validation controls. Organizations should ensure that Firefox installations are updated to version 153 or later where the vulnerability has been addressed through enhanced interface protection mechanisms. The fix typically involves strengthening the browser's security model to prevent malicious overlays from interfering with legitimate user interface interactions while preserving the functionality of legitimate extensions.
This vulnerability aligns with CWE-1021, which specifically addresses "Improper Restriction of Rendered UI Layers or Frames," and maps to ATT&CK technique T1531, "Modify Existing Program", where adversaries manipulate application interfaces to achieve their objectives. The remediation approach focuses on strengthening the browser's user interface security boundaries and implementing more rigorous validation of extension behaviors within the mobile browser environment. Security teams should monitor for potential exploitation attempts and ensure comprehensive testing of browser extensions for similar vulnerabilities that could be leveraged in future attacks against mobile browser platforms.
The resolution of this vulnerability demonstrates the ongoing importance of maintaining up-to-date browser security implementations, particularly in mobile environments where user interface manipulation presents unique attack surfaces. Regular security updates and proactive monitoring of browser component vulnerabilities are essential for maintaining robust defense mechanisms against sophisticated attack vectors that target the user interaction layer of modern web browsers.