Overview
CVE-2026-48908 is a critical unauthenticated arbitrary file upload vulnerability affecting the SP Page Builder extension for Joomla, developed by JoomShaper. The vulnerability allows remote attackers to upload and execute arbitrary PHP files on affected installations without authentication.
The vulnerability carries a CVSS score of 10.0 (Critical) and has been added to CISA's Known Exploited Vulnerabilities catalog after evidence of active exploitation.
Affected Component
SP Page Builder extension for Joomla versions prior to 6.6.2.
The vulnerability exists in the asset.uploadCustomIcon endpoint, which fails to properly validate uploaded file types, allowing an attacker to upload PHP files that can then be executed remotely.
Research Context
This research was conducted as part of ongoing learning in vulnerability analysis and responsible security testing. The goal was to understand the vulnerability mechanism, develop detection capabilities, and document findings responsibly.
Technical Summary
The vulnerability stems from unrestricted file upload in the custom icon upload functionality. An unauthenticated attacker can send a crafted request to the vulnerable endpoint with a PHP file payload. Because the file type validation is insufficient, the server accepts and stores the file, which can subsequently be accessed and executed.
Detailed exploitation instructions are not included in this public documentation. The focus is on detection and understanding rather than weaponization.
Testing Environment
Testing was performed in a controlled local lab environment using a vulnerable Joomla installation with the affected SP Page Builder version. No production systems were targeted. All testing was conducted on systems owned by the researcher or explicitly authorized for assessment.
Impact
Successful exploitation allows unauthenticated remote code execution, leading to full server compromise. The vulnerability is considered critical due to the combination of unauthenticated access and the ability to execute arbitrary code.
Disclosure
This research follows responsible disclosure principles. The vulnerability was reported through appropriate channels. Public documentation focuses on detection and remediation rather than exploitation.
The detection tool built for this research is available on GitHub and is intended for authorized security assessment only.
Timeline
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June 2026
Vulnerability publicly disclosed; security updates released in SP Page Builder 6.6.2.
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July 2026
Added to CISA Known Exploited Vulnerabilities catalog; active exploitation observed in the wild.
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August 2026
Research tool published on GitHub for authorized detection and assessment.
References
- GitHub Repository — CVE-2026-48908-by-yora
- Check Point Advisory — CPAI-2026-8722
- CSA Singapore Advisory — Active Exploitation of Joomla Extension Vulnerabilities
- FortiGuard Labs — Joomla SP Page Builder RCE