CVE-2025-35939

Craft CMS stores user-provided content in session files. A remote, unauthenticated attacker can introduce arbitrary content, including PHP code, into session files with known names and locations. If an attacker can access these files, possibly through another vulnerability such as CVE-2024-58136 (or CVE-2025-32432). For context, Yii fixed CVE-2024-4990 then later re-introduced it as CVE-2024-58136. Craft CMS assigned CVE-2025-32432 to the Craft CMS inheritance of CVE-2024-58136.

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. Craft CMS versions 5.7.5 and 4.15.3 have been released to address this issue.