CVE-2026-5478
Vulnérabilité élevée dans Everest Forms – Contact Form, Payment Form, Quiz, Survey & Custom Form Builder (wpeverest)
Description
The Everest Forms plugin for WordPress is vulnerable to Arbitrary File Read and Deletion in all versions up to, and including, 3.4.4. This is due to the plugin trusting attacker-controlled old_files data from public form submissions as legitimate server-side upload state, and converting attacker-supplied URLs into local filesystem paths using regex-based string replacement without canonicalization or directory boundary enforcement. This makes it possible for unauthenticated attackers to read arbitrary local files (e.g., wp-config.php) by injecting path-traversal payloads into the old_files upload field parameter, which are then attached to notification emails. The same path resolution is also used in the post-email cleanup routine, which calls unlink() on the resolved path, resulting in the targeted file being deleted after being attached. This can lead to full site compromise through disclosure of database credentials and authentication salts from wp-config.php, and denial of service through deletion of critical files. Prerequisite: The form must contain a file-upload or image-upload field, and disable storing entry information.
Gravité et risque d'exploitation
CVE-2026-5478 obtient un score CVSS de 8.1/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.95 %, ce qui la place devant 60.7 % des CVE référencées.
Que faire ?
- Vérifiez si Everest Forms – Contact Form, Payment Form, Quiz, Survey & Custom Form Builder (versions 0, <=3.4.4) 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/8641eb53-6a9a-4549-b8ef-e37acbcc7f03?source=cve
- https://plugins.trac.wordpress.org/browser/everest-forms/tags/3.4.4/includes/abstracts/class-evf-form-fields-upload.php#L1306
- https://plugins.trac.wordpress.org/browser/everest-forms/tags/3.4.4/includes/abstracts/class-evf-form-fields-upload.php#L1665
- https://plugins.trac.wordpress.org/browser/everest-forms/tags/3.4.4/includes/abstracts/class-evf-form-fields-upload.php#L1581
- https://plugins.trac.wordpress.org/changeset/3507814/everest-forms