CVE-2026-39292: PHPPageBuilder Remote Code Execution via Unrestricted File Upload

Technical summary

CVE-2026-39292 is an unrestricted file upload vulnerability (CWE-434) in the pagemanager/pagebuilder module of PHPPageBuilder v0.31.0. The vulnerability stems from insufficient validation of both file type and executable content during the upload process. This allows an unauthenticated remote attacker to bypass file restrictions and upload arbitrary files—including executable scripts—to the web server. Once uploaded, an attacker can access and execute the malicious payload, achieving remote code execution in the context of the web application.

Business impact

Successful exploitation allows attackers to execute arbitrary code on servers running the vulnerable version, potentially leading to complete compromise of affected web applications. This can result in unauthorized data access, data modification or deletion, website defacement, establishment of persistence mechanisms, lateral movement within the network, or use of the compromised server as a launching point for further attacks. Organizations using this page builder for critical business websites face significant operational and reputational risk.

Affected systems

Falco Solutions PHPPageBuilder v0.31.0 is confirmed vulnerable. Organizations running this version should immediately identify all instances within their infrastructure. Administrators should verify their installed version through the application settings or file system. Newer or older versions have not been confirmed as affected by this specific vulnerability; however, security teams should check vendor advisories for comprehensive affected version ranges and determine upgrade paths accordingly.

Exploitability

This vulnerability is network-accessible and requires no authentication or user interaction for exploitation (CVSS vector AV:N/AC:L/PR:N/UI:N). An attacker can craft a malicious upload request from the internet and execute it directly. The attack complexity is low, making exploitation straightforward for adversaries with basic technical capability. The lack of authentication requirements significantly increases the threat surface.

Remediation

The primary remediation is to upgrade PHPPageBuilder to a patched version released after v0.31.0. Verify the available patched version against the Falco Solutions security advisory or vendor website. If an immediate upgrade is not feasible, implement compensating controls: restrict file upload functionality at the web server or firewall level, apply strict input validation on the upload endpoint, configure the web server to prevent execution of uploaded files in the upload directory (e.g., disable script execution in the uploads folder), and monitor upload directories for suspicious activity.

Patch guidance

Contact Falco Solutions or check their official security advisories and release notes to identify the patched version addressing CVE-2026-39292. Obtain the patch from the vendor's official distribution channels. Test the upgrade in a non-production environment to verify compatibility with your configuration and any custom extensions. After validation, schedule maintenance windows to deploy the patch across all affected instances. Document the patching process and verify successful remediation post-deployment.

Detection guidance

Monitor web server logs and application logs for unusual file upload requests to the pagemanager/pagebuilder module endpoints. Look for uploads of executable file types (.php, .php5, .phtml, .exe, .sh, .jsp, etc.) or files with mismatched extensions. Implement file integrity monitoring on the uploads directory to detect newly created or modified executable files. Review web application firewall (WAF) logs for rejected or suspicious upload attempts. Consider deploying intrusion detection signatures that identify exploitation attempts against file upload functionality.

Why prioritize this

This vulnerability warrants immediate attention due to its HIGH severity (CVSS 7.3), network accessibility, lack of authentication requirements, and direct path to remote code execution. The unrestricted file upload capability represents one of the most dangerous classes of web application vulnerabilities. Any internet-facing instance is at immediate risk of compromise. Prioritize patching before addressing lower-severity issues.

Risk score, explained

The CVSS 3.1 score of 7.3 (HIGH) reflects a network-exploitable vulnerability with low attack complexity and no authentication barrier. The impact metrics indicate partial loss of confidentiality, integrity, and availability—consistent with remote code execution scenarios where an attacker can read files, modify content, and disrupt services. The absence of scope change (S:U) indicates the impact is limited to the vulnerable component itself, though in practice, code execution often enables broader compromise.

Frequently asked questions