GuppY CMS 6.00.10 is vulnerable to Unrestricted File Upload which allows remote attackers to execute arbitrary code by uploading a php file.

The WP Guppy WordPress plugin before 1.3 does not have any authorisation in some of the REST API endpoints, allowing any user to call them and could lead to sensitive information disclosure, such as usernames and chats between users, as well as be able to send messages as an arbitrary user

Multiple cross-site scripting (XSS) vulnerabilities in GuppY before 4.6.28 allow remote attackers to inject arbitrary web script or HTML via the (1) "an" parameter to agenda.php or (2) cat parameter to mobile/thread.php.

SQL injection vulnerability in newsletter.php in GuppY 4.5.18 allows remote attackers to execute arbitrary SQL commands via the lng parameter.

Directory traversal vulnerability in inc/includes.inc in GuppY 4.6.3 allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the selskin parameter to index.php. NOTE: this can be leveraged for remote file inclusion by including inc/boxleft.inc and specifying a URL in the xposbox[L][] array parameter.

Directory traversal vulnerability in error.php in GuppY 4.6.3, 4.5.16, and earlier allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the id parameter. NOTE: this can be leveraged to bypass authentication and upload arbitrary files by including admin/inc/upload.inc and specifying certain multipart/form-data input for admin/inc/upload.inc.

GuppY 4.0 allows remote attackers to delete arbitrary files via a direct request to install/install.php, then selecting "Installation propre" (cleanup.php) and then "Suppression des fichiers d'installation" (delete.php).

Multiple static code injection vulnerabilities in error.php in GuppY 4.5.16 and earlier allow remote attackers to inject arbitrary PHP code into a .inc file in the data/ directory via (1) a REMOTE_ADDR cookie or (2) a cookie specifying an element of the msg array with an error number in the first dimension and 0 in the second dimension, as demonstrated by msg[999][0].

Directory traversal vulnerability in dwnld.php in GuppY 4.5.11 allows remote attackers to overwrite arbitrary files via a "%2E." (mixed encoding) in the pg parameter.

Multiple directory traversal vulnerabilities in GuppY 4.5.9 and earlier allow remote attackers to read and include arbitrary files via (1) the meskin parameter to admin/editorTypetool.php, or the lng parameter to the in admin/inc scripts (2) archbatch.php, (3) dbbatch.php, and (4) nwlmail.php.