WordPress Gravity Forms plugin <= 2.9.30 - Reflected Cross-Site Scripting via 'form_ids' Parameter vulnerability

Reflected Cross-Site Scripting via 'formids' Parameter vulnerability discovered by Anthony Cihan Hann1bl3L3ct3r - Obviam in WordPress Plugin Gravity Forms versions = 2.9.30...

CVE-2026-4406 Gravity Forms <= 2.9.30 - Reflected Cross-Site Scripting via 'form_ids' Parameter

The Gravity Forms plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the formids parameter in the gformgetconfig AJAX action in all versions up to, and including, 2.9.30. This is due to the GFCommon::sendjson method outputting JSON-encoded data wrapped in HTML comment...

CVE-2026-4406

The CVE concerns Gravity Forms for WordPress (≤ 2.9.30) with a Reflected XSS in the gform_get_config AJAX action via the form_ids parameter. The root cause is that GFCommon::send_json() returns JSON wrapped in HTML comments using echo/wp_die(), sending a text/html header instead of application/js...