What the vulnerability does
01Description
The Gravity Forms plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the legacy chunked upload mechanism in all versions up to, and including, 2.9.21.1. This is due to the extension blacklist not including .phar files, which can be uploaded through the chunked upload mechanism. This makes it possible for unauthenticated attackers to upload executable .phar files and achieve remote code execution on the server, granted they can discover or enumerate the upload path. In order for an attacker to achieve RCE, the web server needs to be set up to process .phar file as PHP via file handler mapping or similar.
Explanation of Vulnerability in Simple Terms
02Summary
Gravity Forms versions up to 2.9.21.1 contain an unrestricted file upload vulnerability. An attacker can upload malicious files to the server without proper validation, potentially leading to remote code execution. This affects all installations of the affected versions. Update to a version newer than 2.9.21.1 immediately.
What an attacker can do
03Attacker Capabilities
Upload malicious files to your server and execute arbitrary code.
Potential impact on your site
04Site Impact
Attackers can gain full control of your site by uploading and executing malicious code.
Conditions required to exploit
05Prerequisites
Network access to the Gravity Forms upload endpoint; no authentication required.
Key dates
06Disclosure timeline
November 18, 2025
CVE published
April 8, 2026
Record updated
