CVE-2026-81812 in Website Builder Plugin
Summary
by MITRE • 10/22/2026
The Elementor Website Builder WordPress plugin before 4.3.5 does not sanitize uploaded SVG files on every upload route, allowing users with the Author role and above to upload a file containing JavaScript, which will run in the browser of any user who opens it. Exploitation requires unfiltered file uploads to be enabled in the Elementor Website Builder WordPress plugin before 4.3.5 settings, which is not the default.
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Analysis
by VulDB Data Team • 10/22/2026
The vulnerability identified in versions of the Elementor Website Builder for WordPress prior to version 4.3.5 represents a significant security flaw related to improper input validation and sanitization of uploaded files. Specifically, the application fails to adequately sanitize Scalable Vector Graphics (SVG) files across all available upload routes within the plugin's architecture. This deficiency allows authenticated users with an Author role or higher privileges to bypass existing security controls by uploading malicious SVG payloads that contain embedded JavaScript code. The core technical issue stems from inconsistent filtering mechanisms where certain entry points for file uploads do not apply the same rigorous sanitization protocols as others, creating a gap in the defense-in-depth strategy employed by the plugin.
From an operational perspective, this vulnerability facilitates Stored Cross-Site Scripting attacks when specific configuration conditions are met. The exploitation of this flaw requires that unfiltered file uploads be explicitly enabled within the Elementor settings, which is not the default configuration but remains a viable option for site administrators seeking greater flexibility in media handling. Once such a setting is active, an attacker with sufficient privileges can upload a crafted SVG file containing executable JavaScript. When another user views or interacts with content associated with this uploaded asset, the malicious script executes within their browser context. This execution occurs under the trust relationship established by the victim's session cookies and permissions, potentially leading to account takeover, defacement of the website, or redirection to phishing sites depending on the payload delivered by the attacker.
The classification of this vulnerability aligns with CWE-20 Improper Input Validation and CWE-79 Cross-site Scripting in its stored variant. The failure to sanitize SVG files specifically highlights a gap in handling complex file formats that can contain executable code within their XML structure, a common pitfall for web applications that do not strictly enforce MIME type validation or strip dangerous tags such as script elements from vector graphics. Furthermore, the requirement of specific administrative configuration to enable exploitation places this activity within the context of ATT&CK technique T1505.003 Web Shell: Stored Web Component, although in this case, it is used for XSS rather than direct server-side code execution. The privilege level required indicates that while external attackers cannot exploit this directly without prior compromise or social engineering to gain Author-level access, insider threats or compromised accounts pose a severe risk vector.
Mitigation strategies must focus on both immediate remediation and long-term security hardening. Administrators running affected versions of the Elementor plugin should upgrade immediately to version 4.3.5 or later, where these sanitization gaps have been addressed in all upload routes. In environments where upgrading is not immediately feasible, it is critical to ensure that unfiltered file uploads remain disabled within the plugin settings unless absolutely necessary for legitimate business operations. Additionally, organizations should implement Web Application Firewall rules capable of detecting and blocking SVG files containing script tags or other executable JavaScript patterns. Regular security audits focusing on media upload functionalities are recommended to identify similar inconsistencies in input validation across different plugins and themes integrated into the WordPress ecosystem.