CVE-2026-19804s2Member <= 260814 - Unauthenticated Remote Code Execution via 'first_name' Parameter in PayPal Proxy Return
Updated under an hour ago ()
Does this affect you?
It affects clavaque s2Member – Excellent for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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.
- CVSS
- 8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-94
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Wordfence
- NVD analysis
- Deferred
- Record last updated
- Sep 25, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
clavaque s2Member – Excellent for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions clavaque:s2member_excellent_for_all_kinds_of_memberships_content_restriction_paywalls_and_member_access_subscriptions (from the name) | through 260814 | CNA record |
References
- https://www.wordfence.com/threat-intel/vulnerabilities/id/e87da8fa-04cc-4b9a-9dde-be7d4f2bd76e?source=cve
- https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/utilities.inc.php#L49
- https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/tracking-codes.inc.php#L71
- https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-return-in-subscr-or-wa-w-level.inc.php#L311
- https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-return-in-subscr-or-wa-w-level.inc.php#L319
- https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-utilities.inc.php#L92
- https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-utilities.inc.php#L185
- https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-checkout-in.inc.php#L736
- https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/paypal-return-in.inc.php#L47
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3671073%40s2member&new=3671073%40s2member
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.