{"id":"CVE-2026-19804","published":"2026-09-25T08:16:40.383","lastModified":"2026-09-25T14:17:18.497","description":"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.","cvssScore":8.8,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwes":["CWE-94"],"vendors":[],"products":[],"references":[{"url":"https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-checkout-in.inc.php#L736","tags":[]},{"url":"https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-return-in-subscr-or-wa-w-level.inc.php#L311","tags":[]},{"url":"https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-return-in-subscr-or-wa-w-level.inc.php#L319","tags":[]},{"url":"https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-return-in.inc.php#L47","tags":[]},{"url":"https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-utilities.inc.php#L185","tags":[]},{"url":"https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-utilities.inc.php#L92","tags":[]},{"url":"https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/tracking-codes.inc.php#L71","tags":[]},{"url":"https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/utilities.inc.php#L49","tags":[]},{"url":"https://plugins.trac.wordpress.org/changeset?reponame=&old=3671073%40s2member&new=3671073%40s2member","tags":[]},{"url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/e87da8fa-04cc-4b9a-9dde-be7d4f2bd76e?source=cve","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"The flaw allows remote code execution via the 'first_name' parameter, due to insufficient sanitization and exposure of the site-global proxy verification key.","exploitability":"Exploitation requires knowledge of the Signup Tracking Codes template and the site-global proxy verification key, making it moderately hard to exploit.","blast_radius":"If exploited, unauthenticated attackers could execute code on the server, potentially leading to full server compromise.","remediation":"Disable the affected feature or upgrade to the latest version of s2Member, specifically 260815 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["rce","web","wp-plugin","auth-bypass"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-09-29T09:04:20.400Z"}}