Vulnerabilidad · Publicado 25/09/2026
El plugin s2Member para WordPress presenta una vulnerabilidad alta (CVSS 8.8) de ejecución remota de código en versiones hasta 260814. La validación insuficiente del parámetro 'first_name' permite a atacantes ejecutar código PHP arbitrario en servidores vulnerables. Afecta directamente a plataformas de membresías, paywalls de contenido y sistemas de suscripción implementados en sitios web de empresas en México y LATAM.
The s2Member – Excellent for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 260814 via the 'first_name' parameter parameter. This is due to insufficient sanitization of the first_name parameter via esc_refs(), which strips only regex backreferences and not PHP tags, before substitution into the eval'd Signup Tracking Codes template, combined with disclosure of the site-global proxy verification key that allows PayPal postback verification to be bypassed. This makes it possible for unauthenticated attackers to execute code on the server. Successful exploitation requires that the site administrator has configured a Signup Tracking Codes template containing the %%first_name%% placeholder (a documented, GUI-supported feature) and that the attacker has obtained the site-global proxy verification key, which is exposed in plaintext in the JSON response of any PayPal Checkout AJAX request on the target site.
Score: 8.8/10 — Severidad: HIGH — Estado NIST: Received
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-94
Publicado en NIST NVD.