Composer Getgrav/grav vulnerabilities

Grav before 2.0.16 allows sandboxed Twig templates to access sensitive User fields through allow-listed offsetGet() and offsetexists() methods that lack field filtering. Attackers with page-edit permissions can call offsetGet() on User objects to extract hashed passwords and 2FA secrets, enabling offline password cracking and authentication bypass.

Grav CMS before 2.0.16 fails to filter system, site, and theme configuration arrays in sandboxed Twig renders, allowing content editors to read sensitive configuration values. Attackers with page-content edit access can access raw configuration arrays including secrets like cache credentials by using dot notation in Twig templates, bypassing the config_denied_paths restrictions.

Grav CMS before 2.0.16 contains a path traversal vulnerability in the media_directory() Twig function that fails to validate filesystem paths, allowing authenticated users to enumerate and access files outside intended scope. Attackers with page authoring privileges can supply arbitrary filesystem paths to media_directory() and use the allow-listed filepath accessor on Medium objects to read file contents of any file matching configured media extensions that the web server process can access.

Grav before 2.0.14 contains a stored cross-site scripting vulnerability in the Security::detectXss() function (system/src/Grav/Common/Security.php). All XSS detection patterns use the PCRE /u (UTF-8) modifier, so a single invalid UTF-8 byte anywhere in page content causes preg_match() to return false for every pattern, silently bypassing the save-time XSS safety gate (Validation::checkSafety()). An authenticated attacker with page-edit permissions (without the security.xss_whitelist privilege) can store malicious JavaScript that executes in the browser of a visitor who views the affected page.

Grav before 2.0.15 contains a path traversal vulnerability in the static asset server within index.php that uses string prefix matching instead of directory-boundary validation. Unauthenticated attackers can access files in sibling directories by exploiting directory names that extend the base path string, such as requesting assets-secret when assets is the configured base.

grav before v1.7.49.5 has a Stored Cross-Site Scripting (Stored XSS) vulnerability in the page editing functionality. An authenticated low-privileged user with permission to edit content can inject malicious JavaScript payloads into editable fields. The payload is stored on the server and later executed when any other user views or edits the affected page.