CVE-2026-19857: unknown formidable forms Injection

Vulnerability summary

CVE-2026-19857 is a medium (CVSS 6.5) Injection vulnerability in unknown formidable forms. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 7.9% of scored vulnerabilities. 1 public exploit is recorded. Fixed in 6.35.

Timeline

1. 16-09-2026
   PublishedVulnerability first disclosed.
2. 16-09-2026
   Last modifiedVulnerability information updated.

Description

The Formidable Forms WordPress plugin before 6.35 does not prevent a request-derived value from reaching the WordPress shortcode parser when it substitutes a supported token into a form's custom HTML, allowing unauthenticated visitors to have arbitrary shortcodes, with attacker-chosen attributes, executed server-side on any page displaying an affected form.

• CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
• CWE-94Improper Control of Generation of Code ('Code Injection')The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.