Kirki – Freeform Page Builder, Website Builder & Customizer <= 6.3.1 - Unauthenticated Stored Cross-Site Scripting via Registration Metadata

Summary

The Kirki – Freeform Page Builder, Website Builder & Customizer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via registration metadata in all versions up to, and including, 6.3.1 This is due to insufficient escaping in `ExceptionalElements::image_element()`, which concatenates a user-meta value straight into an `<img src="…">` attribute. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute whenever a user accesses a page rendering a Kirki users collection whose image element is bound to one of the nine registration meta fields. Requires public user registration to be enabled and a published page carrying a `kirki-register` element, which prints the required element nonce into the public markup.

Timeline

1. Oct 7, 2026, 5:30 AM UTCCVE published
2. Oct 7, 2026, 4:08 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: partial

3. Oct 7, 2026, 5:05 PM UTCRecord last updated

Affected versions

• themeum Kirki – Freeform Page Builder, Website Builder & Customizer

  through 6.3.1

References 11