Snuffleupagus is a PHP security module designed to harden PHP environments by mitigating common bug classes and providing virtual patching capabilities. The vulnerability CVE-2026-22034 arises in Snuffleupagus versions earlier than 0.13.0 when the non-default upload validation feature is enabled and configured to use validation scripts that depend on the Vulcan Logic Disassembler (VLD) extension. The core issue is that if the VLD extension is not available to the PHP CLI SAPI (Server API), the module fails to securely handle multipart POST file uploads. Instead of rejecting or safely handling these files, Snuffleupagus erroneously evaluates all uploaded files as PHP code. This 'failing open' behavior (CWE-636) allows attackers to upload malicious PHP code via multipart POST requests, leading to remote code execution (RCE) without requiring authentication or user interaction. The vulnerability has a CVSS 4.0 score of 9.2, reflecting its critical severity due to network exploitability, no required privileges, and no user interaction. The flaw impacts confidentiality, integrity, and availability of affected systems. The issue was addressed in Snuffleupagus version 0.13.0 by correcting the handling logic to fail securely when VLD is unavailable. No known exploits are currently reported in the wild, but the high severity and ease of exploitation make this a significant threat to PHP environments using vulnerable Snuffleupagus configurations.

For European organizations, this vulnerability poses a critical risk to web servers running PHP with Snuffleupagus versions prior to 0.13.0, especially those that have enabled the upload validation feature with VLD-based scripts. Successful exploitation can lead to remote code execution, allowing attackers to execute arbitrary PHP code on the server, potentially leading to full system compromise, data breaches, defacement, or service disruption. Confidentiality is at risk as attackers can access sensitive data, integrity is compromised through unauthorized code execution, and availability can be affected by denial-of-service attacks or system instability. Organizations relying on PHP-based web applications, including e-commerce, government portals, and critical infrastructure, are particularly vulnerable. The lack of required authentication and user interaction increases the attack surface, making automated exploitation feasible. This threat could impact compliance with European data protection regulations such as GDPR if personal data is compromised. The absence of known exploits currently provides a window for proactive mitigation before widespread attacks occur.

1. Immediately upgrade Snuffleupagus to version 0.13.0 or later, which contains the fix for this vulnerability. 2. If upgrading is not immediately possible, disable the non-default upload validation feature or avoid using VLD-based validation scripts. 3. Ensure the Vulcan Logic Disassembler (VLD) PHP extension is installed and properly enabled for the CLI SAPI if upload validation is required. 4. Implement strict file upload controls at the application level, including whitelisting allowed file types and scanning uploads for malicious content. 5. Employ web application firewalls (WAFs) with rules to detect and block suspicious multipart POST requests containing PHP code. 6. Monitor web server and PHP logs for unusual file upload activity or execution of unexpected PHP scripts. 7. Conduct regular security audits and penetration testing focusing on file upload functionalities. 8. Educate developers and system administrators about secure PHP configuration and the risks of failing open in security modules. 9. Maintain up-to-date backups and incident response plans to quickly recover from potential compromises.