SPIP before 4.3.2, 4.2.16, and 4.1.18 is vulnerable to a command injection issue. A remote and unauthenticated attacker can execute arbitrary operating system commands by sending a crafted multipart file upload HTTP request.
https://vulncheck.com/advisories/spip-upload-rce
https://vozec.fr/researchs/spip-preauth-rce-2024-big-upload/
https://thinkloveshare.com/hacking/spip_preauth_rce_2024_part_2_a_big_upload/