CVE-2026-72697: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in getgrav grav

The media_directory() Twig function in Grav CMS (getgrav/grav) is allow-listed for sandboxed page content but improperly validates its input. When given a plain filesystem path (not a Grav stream), it bypasses containment checks and passes the raw path to the Media constructor, which enumerates files with configured media extensions in that directory. The sandbox allow-list erroneously permits the Medium class's 'filepath' accessor, exposing absolute file paths and enabling reading of file contents. This combination allows an attacker who can inject Twig-processed page content to list and read arbitrary files accessible to the web server. The vulnerability is confirmed in Grav CMS version 2.0.15 and earlier, fixed in 2.0.16.

An attacker with the ability to inject Twig-processed page content can enumerate and read files with certain media extensions anywhere on the filesystem that the web server process can access. This can lead to unauthorized disclosure of sensitive files such as configuration files, documents, and other data matching the media types recognized by Grav. The vulnerability does not require user interaction and does not involve privilege escalation beyond the web server's permissions.

A fix is available in Grav CMS version 2.0.16 that addresses this issue. Users should upgrade to version 2.0.16 or later. Until upgraded, avoid allowing untrusted users to inject Twig-processed content or use sandboxed functions that expose filesystem paths. Review and restrict sandbox allow-lists to ensure that sensitive methods like 'filepath' are not accessible.