CVE-2026-3533 in Jupiter X Core Plugin
Summary
by MITRE • 03/24/2026
The Jupiter X Core plugin for WordPress is vulnerable to limited file uploads due to missing authorization on import_popup_templates() function as well as insufficient file type validation in the upload_files() function in all versions up to, and including, 4.14.1. This makes it possible for Authenticated attackers with Subscriber-level access and above, to upload files with dangerous types that can lead to Remote Code Execution on servers configured to handle .phar files as executable PHP (e.g., Apache+mod_php), or Stored Cross-Site Scripting via .svg, .dfxp, or .xhtml files upload on any server configuration
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Analysis
by VulDB Data Team • 03/28/2026
The vulnerability identified as CVE-2026-3533 affects the Jupiter X Core plugin for WordPress, a widely used theme and page builder solution that has been compromised through inadequate security controls in its file upload functionality. This issue represents a critical authorization flaw that allows authenticated attackers with subscriber-level privileges or higher to exploit the system's import_popup_templates() function without proper access controls. The vulnerability stems from the absence of authorization checks within this function, creating an entry point for unauthorized file operations that should only be accessible to administrators or privileged users.
The technical flaw manifests through insufficient file type validation within the upload_files() function, which fails to properly verify the file extensions and MIME types of uploaded content. This weakness enables attackers to bypass normal security restrictions that would typically prevent the upload of potentially dangerous file types such as .phar, .svg, .dfxp, or .xhtml files. The vulnerability is particularly concerning because it affects all versions of the plugin up to and including version 4.14.1, indicating a long-standing issue that has not been properly addressed in the plugin's security architecture. The lack of proper file validation creates a pathway for attackers to upload malicious files that can be executed or rendered in ways that compromise the entire WordPress installation.
The operational impact of this vulnerability is severe and multifaceted, as it provides attackers with multiple attack vectors depending on the server configuration. When servers are configured to treat .phar files as executable PHP, attackers can upload malicious phar files that will be executed as PHP code, leading to full remote code execution capabilities. This scenario allows attackers to gain complete control over the affected server, potentially leading to data breaches, server compromise, or further lateral movement within network infrastructure. Additionally, the vulnerability enables stored cross-site scripting attacks through the upload of malicious .svg, .dfxp, or .xhtml files, which can be rendered in web browsers and used to execute malicious scripts against other users of the WordPress site. This dual threat capability makes the vulnerability particularly dangerous as it can be exploited for both server-side code execution and client-side attacks against legitimate site visitors.
The security implications extend beyond immediate exploitation as this vulnerability aligns with several common attack patterns documented in the MITRE ATT&CK framework, specifically targeting privilege escalation and code execution techniques. The vulnerability maps to CWE-434, which describes "Unrestricted Upload of File with Dangerous Type," and CWE-22, "Improper Limitation of a Pathname to a Restricted Directory," indicating that the vulnerability involves both improper file type validation and potential path traversal issues. Organizations running affected versions of the Jupiter X Core plugin face significant risk of compromise, as the vulnerability requires minimal privileges to exploit and can lead to complete system takeover. The attack surface is further expanded by the fact that this vulnerability affects a popular WordPress plugin, making it a prime target for automated exploitation tools and increasing the likelihood of widespread compromise across affected installations.
Mitigation strategies should focus on immediate plugin updates to versions that address the authorization and validation flaws, as well as implementing additional security controls such as restricting file upload capabilities, implementing more robust file type validation, and monitoring for suspicious upload activities. Organizations should also consider implementing network-level controls to prevent execution of potentially dangerous file types and ensure that server configurations do not automatically execute .phar files as PHP code. Regular security audits and vulnerability assessments should be conducted to identify similar issues in other plugins and themes, as this vulnerability demonstrates how insufficient access controls and file validation can create significant security risks in content management systems. The vulnerability also highlights the importance of proper authorization checks in web applications, as the missing authorization in the import_popup_templates() function represents a fundamental security flaw that should be addressed through proper access control mechanisms and input validation procedures.