CVE-2026-73340 in Featured Image From URL Plugin
Summary
by MITRE • 08/13/2026
Contributor Cross Site Scripting (XSS) in Featured Image from URL <= 5.3.3 versions.
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Analysis
by VulDB Data Team • 08/13/2026
This vulnerability represents a cross site scripting flaw that affects the Featured Image from URL plugin for WordPress systems. The issue specifically impacts versions up to and including 5.3.3, where the plugin fails to properly sanitize user input when processing URLs for featured image retrieval. The vulnerability stems from insufficient validation and sanitization of external URL parameters that are directly incorporated into HTML output without proper encoding or filtering mechanisms. Attackers can exploit this weakness by crafting malicious URLs containing script tags or other XSS payloads that get executed when the featured image is displayed on a webpage. This creates a persistent threat vector where malicious scripts can be injected into the target website's content, potentially compromising user sessions, stealing cookies, or redirecting visitors to malicious sites. The vulnerability aligns with CWE-79 which specifically addresses cross site scripting flaws in web applications and follows the ATT&CK technique T1059.008 for script injection. The operational impact extends beyond simple data theft as attackers can leverage this vulnerability to perform more sophisticated attacks such as credential harvesting, session hijacking, or even defacement of affected websites. When a victim visits a page containing the maliciously injected content, their browser executes the embedded scripts within the context of the vulnerable site, potentially allowing unauthorized access to user accounts or sensitive data.
The technical implementation of this vulnerability occurs when the plugin processes external URLs for featured image display without adequate input validation. The system accepts URL parameters directly from user input and incorporates them into HTML output without proper sanitization or encoding procedures. This failure in input handling creates an environment where malicious actors can inject JavaScript code through carefully crafted URLs that are then executed in the browser context of legitimate website visitors. The vulnerability is particularly concerning because it operates at the content presentation layer, making it difficult to detect through traditional network monitoring while still providing attackers with significant attack surface. The flaw demonstrates poor secure coding practices related to output encoding and input validation which are fundamental requirements according to OWASP Top Ten security principles.
Mitigation strategies for this vulnerability should include immediate patching of affected systems to version 5.3.4 or later where the XSS protection has been implemented. Organizations should also implement web application firewalls that can detect and block suspicious script injection attempts in URL parameters. Additionally, administrators should consider implementing Content Security Policy headers to restrict script execution within the affected applications. Regular security audits should be conducted to identify similar vulnerabilities in other plugins or custom code implementations. The remediation process must include thorough input validation for all external URL parameters and proper output encoding of dynamic content before rendering. Organizations should also establish monitoring procedures to detect unusual traffic patterns that might indicate exploitation attempts, particularly around URL parameter manipulation. Security teams should maintain awareness of the ATT&CK framework's techniques related to code injection and ensure their incident response procedures include specific handling for XSS vulnerabilities in CMS systems.