CVE-2026-8871: Thomstark Formidable Kinetic

Medium severity, CVSS 6.4. EPSS: 0.3% chance of exploitation in the next 30 days.

The Formidable Kinetic plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'kinetic_link' shortcode in versions up to, and including, 1.1.01. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes (notably 'window', 'class', and 'label') in the FrmKinetic::link() function, which are concatenated directly into HTML attributes of an anchor tag. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Affected products

• Thomstark Formidable Kinetic: up to and including 1.1.01

Published 2026-05-27. Last modified 2026-06-17.