SPIP 4.0.0 is affected by a Cross Site Request Forgery (CSRF) vulnerability in ecrire/public/aiguiller.php, ecrire/public/balises.php, ecrire/balise/formulaire_.php. To exploit the vulnerability, a visitor must visit a malicious website which redirects to the SPIP website. It is also possible to combine XSS vulnerabilities in SPIP 4.0.0 to exploit it. The vulnerability allows an authenticated attacker to execute malicious code without the knowledge of the user on the website (CSRF).