CVE-2026-15826
The User Profile Builder plugin for WordPress is vulnerable to Authentication Bypass via Type Confusion in versions up to, and including, 3.16.4. This is due to the wppb_log_in_user() function calling absint() on the return value of wp_insert_user() before performing an is_wp_error() check — when a registration is submitted with a 61–70 character username, WordPress core rejects it with a WP_Error object, but absint() coerces that object to the integer 1 before the error check can short-circuit execution, causing the plugin to bind and return a transient-backed autologin nonce tied to user ID 1. This makes it possible for unauthenticated attackers to log in as the site's Administrator account (user ID 1), resulting in full administrative takeover of the site.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 9.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 3.90%
- Percentil entre todas las CVEs puntuadas: 90
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1190Exploit Public-Facing Applicationinitial access95 % - Impacto principal
T1078.001Default Accountsstealth · persistence · privilege escalation · initial access90 %
CVE de aplicación web expuesta (AV:N, PR:N, UI:N) que permite bypass de autenticación explotando confusión de tipos en PHP. Atacante no autenticado obtiene sesión como administrador (T1078.001), control total de cuentas (T1098.002) y privilegios root (T1068).
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-704
Referencias
- https://plugins.trac.wordpress.org/browser/profile-builder/tags/3.16.4/features/functions.php#L1481
- https://plugins.trac.wordpress.org/browser/profile-builder/tags/3.16.4/front-end/class-formbuilder.php#L262
- https://plugins.trac.wordpress.org/browser/profile-builder/tags/3.16.4/front-end/class-formbuilder.php#L364
- https://plugins.trac.wordpress.org/browser/profile-builder/tags/3.16.4/front-end/class-formbuilder.php#L742
- https://plugins.trac.wordpress.org/browser/profile-builder/tags/3.16.4/front-end/class-formbuilder.php#L945
- https://plugins.trac.wordpress.org/browser/profile-builder/tags/3.16.4/front-end/default-fields/username/username.php#L28
- https://plugins.trac.wordpress.org/browser/profile-builder/tags/3.16.4/front-end/default-fields/username/username.php#L49
- https://plugins.trac.wordpress.org/changeset/3609855/profile-builder
- https://www.wordfence.com/threat-intel/vulnerabilities/id/9f606fba-f779-42ea-a160-6c3b20dc5e79?source=cve
JSON original (NVD)
Mostrar
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{
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"role": "CISA Coordinator",
"options": [
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{
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{
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"version": "2.0.3",
"timestamp": "2026-08-17T15:56:57.390314Z"
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"cvssMetricV31": [
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"affected": [
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"affectedData": [
{
"vendor": "cozmoslabs",
"product": "User Profile Builder – Beautiful User Registration Forms, User Profiles & User Role Editor",
"versions": [
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"published": "2026-08-15T07:16:19.280",
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"descriptions": [
{
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"value": "The User Profile Builder plugin for WordPress is vulnerable to Authentication Bypass via Type Confusion in versions up to, and including, 3.16.4. This is due to the wppb_log_in_user() function calling absint() on the return value of wp_insert_user() before performing an is_wp_error() check — when a registration is submitted with a 61–70 character username, WordPress core rejects it with a WP_Error object, but absint() coerces that object to the integer 1 before the error check can short-circuit execution, causing the plugin to bind and return a transient-backed autologin nonce tied to user ID 1. This makes it possible for unauthenticated attackers to log in as the site's Administrator account (user ID 1), resulting in full administrative takeover of the site."
}
],
"lastModified": "2026-08-20T12:48:10.287",
"sourceIdentifier": "security@wordfence.com"
}