CVE-2025-35939

Name of the Vulnerable Software and Affected Versions Craft CMS versions prior to 4.15.3 Craft CMS versions prior to 5.7.5

Description Craft CMS stores arbitrary content provided by unauthenticated users in session files. This content could be accessed and executed, possibly using an independent vulnerability. Craft CMS redirects requests that require authentication to the login page and generates a session file on the server at /var/lib/php/sessions. Such session files are named sess [session value], where [session value] is provided to the client in a Set-Cookie response header. Craft CMS stores the return URL requested by the client without sanitizing parameters. Consequently, an unauthenticated client can introduce arbitrary values, such as PHP code, to a known local file location on the server.

Recommendations For versions prior to 4.15.3, update to version 4.15.3 or later to address this issue. For versions prior to 5.7.5, update to version 5.7.5 or later to address this issue.