SPIP before 4.1.14 and 4.2.x before 4.2.8 allows XSS via the name of an uploaded file. This is related to javascript/bigup.js and javascript/bigup.utils.js.
ecrire/public/assembler.php in SPIP before 4.1.13 and 4.2.x before 4.2.7 allows XSS because input from _request() is not restricted to safe characters such as alphanumerics.
SPIP before 4.2.1 allows Remote Code Execution via form values in the public area because serialization is mishandled. The fixed versions are 3.2.18, 4.0.10, 4.1.8, and 4.2.1.
SPIP v4.1.5 and earlier was discovered to contain a SQL injection vulnerability via the _oups parameter. This vulnerability allows attackers to execute arbitrary code via a crafted POST request.