CVE-2026-1405 is a critical security vulnerability identified in the Slider Future plugin for WordPress, developed by franchidesign. The flaw resides in the 'slider_future_handle_image_upload' function, which lacks proper validation of uploaded file types. This deficiency allows unauthenticated attackers to upload arbitrary files, including potentially malicious scripts, to the server hosting the vulnerable WordPress site. Since the plugin accepts file uploads without restricting dangerous file types, attackers can upload web shells or other executable code, leading to remote code execution (RCE). The vulnerability affects all versions up to and including 1.0.5. The CVSS 3.1 base score is 9.8, reflecting the high impact on confidentiality, integrity, and availability, combined with the ease of exploitation (no privileges or user interaction required). Although no public exploits have been reported yet, the vulnerability's nature makes it a prime target for attackers aiming to compromise WordPress sites. The absence of patch links suggests that a fix may not yet be available, increasing the urgency for mitigation. This vulnerability falls under CWE-434, which concerns unrestricted file upload vulnerabilities that can lead to severe consequences such as server takeover.

For European organizations, this vulnerability poses a significant risk, especially for those relying on WordPress websites with the Slider Future plugin installed. Successful exploitation can lead to full server compromise, data breaches, defacement, or use of the server as a pivot point for further attacks. Confidential information stored on the server can be exfiltrated, altered, or destroyed, impacting business operations and regulatory compliance (e.g., GDPR). The availability of the website or service can be disrupted, causing reputational damage and financial loss. Given the critical severity and ease of exploitation, attackers could automate attacks at scale, targeting multiple vulnerable sites across Europe. Organizations in sectors such as e-commerce, government, education, and media, which often use WordPress, may be particularly vulnerable. The lack of authentication requirement means that even external attackers without credentials can exploit this flaw, increasing the attack surface.

1. Immediately audit all WordPress sites for the presence of the Slider Future plugin and identify affected versions (up to 1.0.5). 2. If a vendor patch is released, apply it promptly. In the absence of an official patch, disable or remove the Slider Future plugin to eliminate the attack vector. 3. Implement strict web application firewall (WAF) rules to detect and block attempts to upload files with dangerous extensions or suspicious payloads targeting the vulnerable upload function. 4. Restrict file upload permissions on the server and ensure uploaded files are stored outside the web root or in directories with no execute permissions. 5. Monitor server logs for unusual upload activity or web shell execution attempts. 6. Employ intrusion detection/prevention systems (IDS/IPS) tuned to detect exploitation attempts of this vulnerability. 7. Educate site administrators about the risks of using outdated plugins and enforce regular plugin updates and vulnerability scanning. 8. Consider implementing Content Security Policy (CSP) headers and other hardening measures to limit the impact of potential code execution.