CVE-2026-42842

Grav Form Plugin before 9.1.22 fails to verify page authorization when resolving forms by name across pages, allowing anonymous visitors to execute form actions defined on login-restricted or unpublished pages. Attackers can POST to any public page with a restricted form's name to trigger save, upload, email, or call actions without authentication.

The Grav Form plugin (getgrav/grav-plugin-form) versions 8.0.6 through 9.1.19 select the reCAPTCHA version to validate based solely on which response field key is present in the submitted payload. On a site configured for reCAPTCHA v3, an anonymous attacker can place their v3 token under the v2 field name (g-recaptcha-response instead of token), causing validation to use the v2 branch, which never applies the score threshold or verifies the expected action. This results in a complete bypass of reCAPTCHA v3 bot protection. The issue is fixed in version 9.1.20.

Grav Form Plugin before 9.1.19 fails to escape field-definition properties including prepend, append, spacer text, section text, and select option labels in form templates. Attackers with form authoring privileges can inject arbitrary HTML and JavaScript that executes for all form visitors through unescaped |raw filters and unquoted attributes.

Grav Form plugin before version 9.1.15 contains a stored cross-site scripting vulnerability in radio and toggle field option labels rendered with the Twig |raw filter. Attackers with form authoring permissions can inject HTML and script payloads in option labels that execute in the browsers of visitors and administrators viewing the form.

The Grav form plugin (getgrav/grav-plugin-form) before version 9.1.13 contains an open redirect vulnerability. Since v9.1.11, the redirect process action evaluates user-supplied form data inside Twig expressions, and Grav::redirect() accepts external URLs without origin validation. An unauthenticated user can supply a malicious URL, causing a 302 redirect to an arbitrary external site.