Grav versions before 1.10.55 contain a path traversal vulnerability in the admin plugin's Save As action that fails to validate the language code parameter. An authenticated admin user with admin.pages.create permission can supply directory traversal sequences in the lang POST field to write arbitrary .md files outside the pages directory with attacker-controlled content.

Grav Shortcode Core before 6.2.5 contains stored cross-site scripting vulnerabilities in the [lorem] tag parameter and [details] summary parameter that are written to rendered pages without escaping. Attackers with page-edit access can inject arbitrary HTML and JavaScript that executes in the browsers of all page visitors, including administrators.

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 Admin (getgrav/grav-plugin-admin2) versions <= 2.0.19 contain a stored cross-site scripting vulnerability in the tHtml() function (src/lib/stores/i18n.svelte.ts), which substitutes untrusted parameters such as usernames into translation templates before parsing the result as markdown. Grav's server-side username validation (DataUser::isValidUsername) blocks filesystem-dangerous characters but not <, >, ", or ', allowing an attacker to register a username containing an HTML payload. When an administrator views a UI surface that renders the username through tHtml()—such as the two-factor force-disable confirmation prompt or the 'page is locked' editor notice—the payload executes in their authenticated session. Fixed in 2.0.21.

Grav versions 2.0.0 through 2.0.17 fail to apply save-time XSS detection to modular pages, allowing authenticated page editors to store Twig-assembled XSS payloads. Attackers with page-edit rights can create modular pages with malicious Twig code that executes in visitor browsers when the parent page is rendered, including in administrator sessions.