CVE-2026-63048 in Page Builder CK Plugin
Summary
by MITRE • 07/22/2026
The Joomla extension Page Builder CK is vulnerable to an authenticated arbitrary file upload, leading to RCE.
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Analysis
by VulDB Data Team • 07/22/2026
The vulnerability in Joomla extension Page Builder CK represents a critical security flaw that allows authenticated attackers to upload arbitrary files to the server, potentially enabling remote code execution. This issue arises from insufficient input validation and inadequate file type restrictions within the extension's file upload functionality. The vulnerability exists because the application fails to properly sanitize user-supplied filenames and file contents before processing them, creating an attack vector where malicious actors can bypass security controls to deploy malicious payloads.
From a technical perspective, this vulnerability maps directly to CWE-434 which describes "Unrestricted Upload of File with Dangerous Type" and aligns with ATT&CK technique T1505.003 for "Download and Execute" operations. The flaw occurs when authenticated users with appropriate privileges attempt to upload files through the extension's interface, where the system does not adequately verify file extensions, MIME types, or content signatures. This allows attackers to upload web shells or other malicious executables that can be executed within the context of the web server.
The operational impact of this vulnerability is severe as it provides attackers with persistent access to the target system once they have obtained valid credentials. Successful exploitation enables full control over the affected Joomla installation, allowing attackers to execute arbitrary commands, escalate privileges, exfiltrate sensitive data, and potentially use the compromised system as a pivot point for further attacks within the network infrastructure. The vulnerability affects not only the immediate application but also the underlying server environment where Joomla is hosted.
Mitigation strategies should include immediate patching of the Page Builder CK extension to the latest secure version that addresses the file upload validation issues. Organizations must implement strict file type filtering and content validation mechanisms, enforce proper access controls, and monitor upload directories for suspicious activity. Additionally, security measures such as web application firewalls, input sanitization, and regular security audits should be deployed to prevent similar vulnerabilities from occurring in other components of the Joomla ecosystem. Network segmentation and least privilege principles should also be enforced to limit the potential damage from successful exploitation attempts.