CVE-2025-9515: 
WordPress vulnerability analysis and mitigation

The Multi Step Form plugin for WordPress contains a critical vulnerability (CVE-2025-9515) discovered in versions up to and including 1.7.25. The vulnerability was disclosed on September 5, 2025, and allows authenticated attackers with administrator-level access to upload arbitrary files to the affected site's server through the import functionality, potentially enabling remote code execution (NVD).

The vulnerability stems from missing file type validation in the plugin's import functionality. The issue is tracked as CWE-434 (Unrestricted Upload of File with Dangerous Type) and has received a CVSS v3.1 score of 7.2 (HIGH) with the vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. The vulnerability exists due to insufficient validation of uploaded files during the JSON import process, allowing malicious files to bypass security checks (Wordfence).

If exploited, this vulnerability could allow authenticated administrators to upload arbitrary files to the server, potentially leading to remote code execution. This could give attackers the ability to execute malicious code on the affected website, compromising the entire WordPress installation (NVD).

The vulnerability has been patched in version 1.7.26 of the Multi Step Form plugin. The update includes enhanced file type validation for JSON imports, PHP code detection in uploaded files, improved JSON structure validation, and automatic cleanup of malicious files. Users are strongly advised to update to version 1.7.26 immediately (GitHub).