CVE-2026-4300

Description

The Robo Gallery plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'Loading Label' setting in all versions up to, and including, 5.1.3. The plugin uses a custom `|***...***|` marker pattern in its `fixJsFunction()` method to embed raw JavaScript function references within JSON-encoded configuration objects. When a gallery's options are rendered on the frontend, `json_encode()` wraps all string values in double quotes. The `fixJsFunction()` method then strips the `"|***` and `***|"` sequences, effectively converting a JSON string value into raw JavaScript code. The Loading Label field (stored as `rbs_gallery_LoadingWord` post_meta) is an `rbstext` type field that is sanitized with `sanitize_text_field()` on save. While this strips HTML tags, it does not strip the `|***...***|` markers since they contain no HTML. When a user inputs `|***alert(document.domain)***|`, the value passes through sanitization intact, is stored in post_meta, and is later retrieved and output within an inline `<script>` tag via `renderMainBlock()` with the quote markers stripped — resulting in arbitrary JavaScript execution. The gallery post type uses `capability_type => 'post'`, allowing Author-level users to create galleries. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses a page containing the gallery shortcode.

Gravité et risque d'exploitation

CVE-2026-4300 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 0.51 %, ce qui la place devant 41.9 % des CVE référencées.

Que faire ?

• Vérifiez si Robo Gallery – Photo & Image Slider (versions <=5.1.3, 0) 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/d8693b7d-693f-450a-89ef-e936a8813ca9?source=cve
• https://plugins.trac.wordpress.org/browser/robo-gallery/trunk/includes/frontend/modules/class/jsoptions.php#L97
• https://plugins.trac.wordpress.org/browser/robo-gallery/tags/5.1.3/includes/frontend/modules/class/jsoptions.php#L97
• https://plugins.trac.wordpress.org/browser/robo-gallery/trunk/includes/frontend/modules/base-grid/layout.v1.php#L101
• https://plugins.trac.wordpress.org/browser/robo-gallery/tags/5.1.3/includes/frontend/modules/base-grid/layout.v1.php#L101
• https://plugins.trac.wordpress.org/browser/robo-gallery/trunk/includes/frontend/modules/base-grid/layout.v1.php#L52
• https://plugins.trac.wordpress.org/browser/robo-gallery/tags/5.1.3/includes/frontend/modules/base-grid/layout.v1.php#L52
• https://plugins.trac.wordpress.org/browser/robo-gallery/trunk/includes/frontend/modules/base-grid/grid/grid.v1.php#L89
• https://plugins.trac.wordpress.org/browser/robo-gallery/tags/5.1.3/includes/frontend/modules/base-grid/grid/grid.v1.php#L89
• https://plugins.trac.wordpress.org/browser/robo-gallery/trunk/includes/frontend/modules/class/jsoptions.php#L87
• https://plugins.trac.wordpress.org/browser/robo-gallery/tags/5.1.3/includes/frontend/modules/class/jsoptions.php#L87
• https://plugins.trac.wordpress.org/browser/robo-gallery/trunk/includes/options/rbs_gallery_options_loading.php#L95
• https://plugins.trac.wordpress.org/browser/robo-gallery/tags/5.1.3/includes/options/rbs_gallery_options_loading.php#L95
• https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3488182%40robo-gallery&new=3488182%40robo-gallery&sfp_email=&sfph_mail=