What the vulnerability does
01Description
The Pie Forms for WP plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 1.6 via the format_classic function. This is due to insufficient file type validation where the validate_classic method validates file extensions and sets error messages but does not prevent the file upload process from continuing. This makes it possible for unauthenticated attackers to upload files with dangerous extensions such as PHP, which makes remote code execution possible. In order to exploit this vulnerability, the attacker needs to guess the directory in which the file is placed (which is a somewhat predictable hash). In addition to that, the file name is generated using a secure hash method, limiting the exploitability of this vulnerability.
Explanation of Vulnerability in Simple Terms
02Summary
Pie Forms allows attackers to upload files without restriction, potentially enabling them to store malicious files on the server. The vulnerability requires specific conditions to exploit but can lead to complete compromise of confidentiality, integrity, and availability. Versions 1.6 and earlier are affected. Update immediately to a version newer than 1.6.
What an attacker can do
03Attacker Capabilities
Upload arbitrary files to the server, potentially including executable code or malware.
Potential impact on your site
04Site Impact
Attackers could store malicious files on your server, leading to data theft, site defacement, or complete server compromise.
Conditions required to exploit
05Prerequisites
Network access; specific attack complexity conditions must be met; no authentication required.
Key dates
06Disclosure timeline
November 18, 2025
CVE published
April 8, 2026
Record updated
