CVE-2026-4336
Vulnérabilité moyenne dans Ultimate FAQ Accordion Plugin (rustaurius)
Description
The Ultimate FAQ Accordion plugin for WordPress is vulnerable to Stored Cross-Site Scripting via FAQ content in all versions up to, and including, 2.4.7. This is due to the plugin calling html_entity_decode() on post_content during rendering in the set_display_variables() function (View.FAQ.class.php, line 746), which converts HTML entity-encoded payloads back into executable HTML, combined with insufficient output escaping in the faq-answer.php template where the decoded content is echoed without wp_kses_post() or any other sanitization. The ufaq custom post type is registered with 'show_in_rest' => true and defaults to 'post' capability_type, allowing Author-level users to create and publish FAQs via the REST API. An Author can submit entity-encoded malicious HTML (e.g., <img src=x onerror=alert()>) which bypasses WordPress's kses sanitization at save time (since kses sees entities as plain text, not tags), but is then decoded back into executable HTML by html_entity_decode() at render time. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in FAQ pages that will execute whenever a user accesses an injected FAQ, either directly or via the [ultimate-faqs] shortcode.
Gravité et risque d'exploitation
CVE-2026-4336 obtient un score CVSS de 6.4/10, soit une gravité moyenne. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.38 %, ce qui la place devant 30.8 % des CVE référencées.
Que faire ?
- Vérifiez si Ultimate FAQ Accordion Plugin (versions 0, <=2.4.7) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.
Références
- https://www.wordfence.com/threat-intel/vulnerabilities/id/5ac3ac02-d496-46cb-9aff-ffeeb8fd80fa?source=cve
- https://plugins.trac.wordpress.org/browser/ultimate-faqs/trunk/ewd-ufaq-templates/faq-answer.php#L2
- https://plugins.trac.wordpress.org/browser/ultimate-faqs/tags/2.4.7/ewd-ufaq-templates/faq-answer.php#L2
- https://plugins.trac.wordpress.org/browser/ultimate-faqs/trunk/views/View.FAQ.class.php#L746
- https://plugins.trac.wordpress.org/browser/ultimate-faqs/tags/2.4.7/views/View.FAQ.class.php#L746
- https://plugins.trac.wordpress.org/browser/ultimate-faqs/trunk/includes/CustomPostTypes.class.php#L84
- https://plugins.trac.wordpress.org/browser/ultimate-faqs/tags/2.4.7/includes/CustomPostTypes.class.php#L84
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3492083%40ultimate-faqs&new=3492083%40ultimate-faqs&sfp_email=&sfph_mail=