CVE-2025-35939
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.
- Listed on CISA KEV (known exploited in the wild)
- SSVC exploitation status: active
- EPSS ≥ 0.10 - elevated exploitation probability
- EPSS percentile: top 3% of all CVEs by exploitation likelihood
- SSVC automatable: yes - attacks can be scripted at scale