SPIP 3.1.x suffer from a Reflected Cross Site Scripting Vulnerability in /ecrire/exec/info_plugin.php involving the `$plugin` parameter, as demonstrated by a /ecrire/?exec=info_plugin URL.
Cross-site scripting (XSS) vulnerability in ecrire/exec/plonger.php in SPIP 3.1.3 allows remote attackers to inject arbitrary web script or HTML via the rac parameter.